Flowering Period Research Articles

The Effects of Mother Tree Size and Flowering Period on Salt Tolerance of <i>Tamarix Austromongolica</i> Seeds in the Yellow River Delta

<i>Tamarix austromongolic</i>a is a two-season flowering plant with a spring and summer flowering period and both flowering periods produce viable seeds, with flowering extending from mid-May to October and seed maturation from mid-June to October. In order to reveal the germination pattern of <i>T. austromongolica</i> seeds in the Yellow River Delta region, this study investigated the salt tolerance of seeds of different age mother trees during the spring and summer flowering periods in the region. Spring and summer flowering seeds of different ground diameter mother trees in the <i>T. austromongolica</i> forest in the region were collected and subjected to seed germination experiments under different concentrations of NaCl solution. The results showed that the diameter grade of the mother tree had a significant impact on seed germination, but had no significant effect on early seedling growth (except for the root length of offspring seedlings during the summer flowering period). As the diameter level of the mother tree increases, the germination rate, germination index, and vitality index of seeds during the spring flowering period first increase and then decrease, with the highest values observed at a ground diameter of 10.0-19.9cm. However, the above indicators of summer flowering seeds gradually decreased with the diameter increasing. There were significant differences in salt tolerance of seeds during different flowering periods. The germination rate and germination index of spring flowering seeds significantly decreased between 11‰ and 15‰, but the effect of salt concentration on summer flowering seed germination was not significant. For the early growth of seedlings, as the salt concentration increased, the root length and seedling height of seed offspring seedlings during spring and summer flowering periods decreased after being higher than 5‰. Compared with spring flowering seeds, summer flowering seeds had higher germination ability and seedling weight under salt stress. Therefore, the salt tolerance of the seeds of <i>T. austromongolica</i> was determined by the size of the mother tree and the flowering period, which is an important strategy for its adaptation to the Yellow River Delta region.

GhGASA14 regulates the flowering time of upland cotton in response to GA3.

The silencing of GhGASA14 and the identification of superior allelic variation in its coding region indicate that GhGASA14 may positively regulate flowering and the response to GA3. Gibberellic acid-stimulated Arabidopsis (GASA), a member of the gibberellin-regulated short amino acid family, has been extensively investigated in several plant species and found to be critical for plant growth and development. However, research on this topic in cotton has been limited. In this study, we identified 38 GhGASAs that were dispersed across 18 chromosomes in upland cotton, and all of these genes had a GASA core domain. Transcriptome expression patterns and qRT-PCR results revealed that GhGASA9 and GhGASA14 exhibited upregulated expression not only in the floral organs but also in the leaves of early-maturing cultivars. The two genes were functionally characterized by virus-induced gene silencing (VIGS), and the budding and flowering times after silencing the target genes were later than those of the control (TRV:00). Compared with that in the water-treated group (MOCK), the flowering period of the different fruiting branches in the GA3-treated group was more concentrated. Interestingly, allelic variation was detected in the coding sequence of GhGASA14 between early-maturing and late-maturing accessions, and the frequency of this favorable allele was greater in high-latitude cotton cultivars than in low-latitude ones. Additionally, a significant linear relationship was observed between the expression level of GhGASA14 and flowering time among the 12 upland cotton accessions. Taken together, these results indicated that GhGASA14 may positively regulate flowering time and respond to GA3. These findings could lead to the use of valuable genetic resources for breeding early-maturing cotton cultivars in the future.

Beyond fire: Flower production naturally occurs and is also influenced by leaf removal in a Neotropical savanna herb.

Several herbaceous species exhibit mass flowering after fires in Neotropical savannas. However, unequivocal evidence of fire dependency and the consequences for plant reproduction are lacking. In nutrient-poor fire-prone savannas, the damage caused by fire and by other means (e.g., leaf removal, but not necessarily having a negative impact) constrains the maintenance and expansion of plant population by affecting the ability of individuals to recover. Therefore, the compensatory responses of plants to both damages should be convergent in such environments. Using Bulbostylis paradoxa-reported to be fire-dependent to flower-as a model, we investigated the role of fire and leaf removal in anticipating the flowering and reproduction periods, and its possible consequences on seedling establishment. We monitored 70 burned individuals, 70 damaged/clipped, and 35 without damage to estimate time for flowering, seed quality and germination parameters. To expand our sampling coverage, we examined high-resolution images from herbarium collections in the SpeciesLink database. For each herbarium image, we recorded the presence or absence of a fire scar, the month of flowering, and the number of flowering stalks. Bulbostylis paradoxa was fire-stimulated but not dependent on fire to flower, with 65.7% of the individuals flowering in the burned area, 48.6% in the clipped, and 11.4% in the control. This was consistent with the analysis of the herbarium images in which 85.7% of the specimens with flowers had fire scars and 14.3% did not. Burned individuals synchronized flowering and produced more viable seeds. However, the seeds might face a period of unsuitable ecological conditions after early to mid-dry season fires. Flowering of unburned plants was synchronized with the onset of the rainy season. Flexibility in flowering and vegetative reproduction by fragmentation confer to this species, and most likely other plants from the herbaceous layer, the capability of site occupation and population persistence in burned and unburned savanna sites.

Comparison of nectar and pollen resources in various Tilia species. A case study from southern Poland

Management of food resources is considered fundamental for supporting insect pollinators, whose abundance shows a downward trend on the global scale. Here, the nectar and pollen production (per flower, per 1 m2 of tree crown), the composition of nectar carbohydrates and the levels of pollen proteins was evaluated in eight Tilia species (Malvaceae) growing in SE Poland. In the warm-summer continental climate, Tilia species can improve nectar and pollen resources mainly in June/July. Although the flowering period of each species is short (8.0–14.7 days), appropriate selection of species can extend the availability of food for more than a month. However, the considerable variations in the flowering onset (11.2–20.1 days) may cause significant inter-seasonal shifts in food accessibility.The nectar with its highly changeable sugar concentration (29.5–77.4%) was composed of sucrose, glucose, and fructose; protein content in pollen was 7.2–16.8%. The mean sugar yield was in the range of 0.95–19.1 g per 1 m2 (T. amuriensis – T. platyphyllos, respectively), whereas the mean pollen yield was 1.37–4.1 g per 1 m2 of tree crown (T. amuriensis – T. × euchlora, respectively). Significant year-to-year fluctuations of sugar and pollen yield in linden trees have to be taken into account in conservation schemes, and the introduction of other flowering plants with more stable sugar and pollen production should be considered in an area with a high density of linden trees. Linden flowers mainly support honey bees; nevertheless, wild pollinators (bumble bees, solitary bees, and dipterans) can also benefit from linden floral resources.

Dual-Model GWAS Analysis and Genomic Selection of Maize Flowering Time-Related Traits.

An appropriate flowering period is an important selection criterion in maize breeding. It plays a crucial role in the ecological adaptability of maize varieties. To explore the genetic basis of flowering time, GWAS and GS analyses were conducted using an associating panel consisting of 379 multi-parent DH lines. The DH population was phenotyped for days to tasseling (DTT), days to pollen-shedding (DTP), and days to silking (DTS) in different environments. The heritability was 82.75%, 86.09%, and 85.26% for DTT, DTP, and DTS, respectively. The GWAS analysis with the FarmCPU model identified 10 single-nucleotide polymorphisms (SNPs) distributed on chromosomes 3, 8, 9, and 10 that were significantly associated with flowering time-related traits. The GWAS analysis with the BLINK model identified seven SNPs distributed on chromosomes 1, 3, 8, 9, and 10 that were significantly associated with flowering time-related traits. Three SNPs 3_198946071, 9_146646966, and 9_152140631 showed a pleiotropic effect, indicating a significant genetic correlation between DTT, DTP, and DTS. A total of 24 candidate genes were detected. A relatively high prediction accuracy was achieved with 100 significantly associated SNPs detected from GWAS, and the optimal training population size was 70%. This study provides a better understanding of the genetic architecture of flowering time-related traits and provides an optimal strategy for GS.

Peliosanthes yangchunensis (Asparagaceae), a new species from Guangdong, China

A new species named Peliosanthes yangchunensis are described, which is endemic to Yangchun, western Guangdong, South China. The new species is closely related to P. macrostegia, but differs from the latter in that the flowers smaller, star-like and with strongly revolute, spreading and narrowly oblong tepals, style conical, ovary hexagonal in cross section, and fruit ovoid-globose, flower period September to October. Comparisons with other closely related species are also provided.

Photosynthetic productivity of soybean (Glycine max L.) crops under various fertilization options and pre-sowing seed treatment

The objective of the research is to determine the impact of basic fertilization options, foliar feeding with organo-mineral fertilizer during critical periods of soy plant development, pre-sowing seed treatment with mycorrhizal biofertilizer, and mycorrhizal inoculant in combination with a fungicide on the dynamics of dry matter accumulation by the plants and the net productivity of photosynthesis in the soy crop. Methods. Field (for studying the interaction of the research object with biotic and abiotic factors); morphophysiological (for biological monitoring of productivity elements development during organogenesis stages); statistical (statistical analysis of research results). Results. The article presents research findings on the accumulation of dry matter by soy plants and the net productivity of photosynthesis in the crop across different growth and development stages. Equations have been calculated to establish the relationship between soy seed yield and the indicators of dry mass accumulation by the plants during the pod-filling phase. Conclusions. In modern agricultural practices aimed at achieving maximum seed yield, cultivation technology should include agronomic measures directed towards meeting the biological needs of the plant throughout the vegetation period and reducing the influence of adverse external factors. The highest levels of dry matter accumulation by plants in the study — 26.8–29.2 g/plant, were noted during the pod filling phase in variants with the application of N15P45K60+N30 fertilization, sowing seeds treated with mycorrhizal biopreparation and fungicide, and foliar feeding with organo-mineral fertilizers during the budding and flowering phases. The maximum indicators of net photosynthetic productivity of the crop in the study (8.52–11.29 g/m2×day compared to 5.46 g/m2×day in the absolute control) were observed during the interphase period of flowering and pod filling in variants with N45P45K60 fertilization. For the optimal seed yield of soybean variety Muza observed in the study, the optimal conditions were provided by a cultivation technology involving the application of N15P45K60+N30 fertilizers, pre-sowing seed treatment with mycorrhizal inoculant in combination with fungicide, as well as foliar feeding with organo-mineral fertilizers during the branching or budding phases, when the plants are forming flowers, pods, and seeds within the pods. Through the combination of these agronomic measures, plants accumulate dry matter during the pod filling phase at 25.9–27.4 g/plant, ensuring the net photosynthetic productivity of the crop during this developmental period at 5.60–6.10 g/m2×day, compared to 20.8 g/plant and 5.46 g/m2×day observed in the absolute control, respectively.

Identification of S-RNase Genotypes of 65 Almond [Prunus dulcis (Mill.) D.A. Webb] Germplasm Resources and Close Relatives

Self-incompatibility (SI) systems in plants prevent self-pollination and mating among relatives, enhancing genetic diversity in nature but posing challenges in almond production and breeding. S-allele composition alongside the flowering periods of these cultivars enables the anticipation of cross-compatibility and optimal cultivar combinations for the allocation of pollinating trees in production. In the current study, 65 materials containing 61 almond (Prunus dulcis) germplasm resources, of which two were hybrids and the remaining four were peach (Prunus persica) germplasms, were used for the S-RNase genotype. The results showed that 55 genomic samples were amplified by PCR to obtain double-banded types, which identified their complete S-RNase genotypes, while the rest of the samples amplified only a single band, identifying one S-RNase gene in the S gene. A total of 30 S-RNase genes were identified in Prunus dulcis, Prunus webbii, Prunus persica, Prunus armeniaca, Prunus salicina, and Prunus cerasifera. Sequence analysis revealed polymorphisms spanning from 313 to 2031 bp within the amplified fragment sequence. The S57-RNase gene exhibited the highest frequency at 31.75% among the identified materials, with S1S57, S10S57, and S7S57 being the predominant S genotypes. A new S-RNase gene, named S65, was identified with a sequencing length of 1483 bp. Its deduced amino acid sequence shared 98.24% similarity with the amino acid sequence of the S-RNase gene on GenBank, with the highest homology. Furthermore, according to the findings, 65 materials belong to eight S genotype cross-incompatibility groups (CIG) and one semi-compatibility or compatibility group (0). Among them, most of the seven main almond germplasm resources and 35 cultivars can be cross-pollinated. The results of the study can lay the foundation for pollinator tree allocation and breeding hybrid parent selection in almond production.

Pollination and pollen plant diversity by Apis cerana cerana during olive flowering based on DNA metabarcoding

AbstractTo understand the role of Apis cerana cerana in olive tree (Olea europaea L.) pollination, pollinators and pollen carried by bees were collected from 11 experimental plots during the flowering period. The abundance and diversity of pollen plant species were investigated using DNA metabarcoding. A total of 583 pollinators were collected and A. cerana cerana accounts for 46.83%. Further analysis revealed a total of 56 families, 136 genera and 195 plant species in bee pollens. O. europaea is the dominant species accounting for 42.02 ± 34.89% and then followed by Sedum japonicum (8.70 ± 16.42%). Diversity index showed that the abundance and diversity of pollen plant species were the highest in Wanzhou (WZ) and lowest in Hechuan (HC). This suggests that Wanzhou sample plot has a greater abundance of plant species to supplement the bee diet. Excessive presence of miscellaneous flowering plants in olive plantations can distract bees from collecting olive tree pollens. Therefore, their abundances can be reduced appropriately while ensuring food diversity for the bees. Based on the abundance of plants in pollens, we recommend that appropriately planting of S. japonicum, Youngia japonica and Vicia villosa in olive plantations with fewer flowering plants could be an effective supplement of bee food. Our results not only contribute to future studies on olive tree pollination but also provide new ideas for enriching flowering plants in or around olive plantations.

Elderberry Leaves with Antioxidant and Anti-Inflammatory Properties as a Valuable Plant Material for Wound Healing.

Sambuci folium (elderberry leaves) have been used in traditional medicine, mainly externally, to treat skin diseases and wounds. Therefore, the aim of this study was to screen the biological activity of elderberry leaves (antioxidant potential and possibility of inhibition of tyrosinase and hyaluronidase enzymes) combined with phytochemical analysis. For this purpose, a phytochemical analysis was carried out. Elderberry leaves of 12 varieties ("Sampo", "Obelisk", "Dwubarwny", "Haschberg", "Haschberg 1", "Koralowy", "Sambo", "Black Beauty", "Black Tower", "Golden hybrid", "Samyl", "Samyl 1") in two growth stages. The compounds from the selected groups, phenolic acids (chlorogenic acid) and flavonols (quercetin), were chromatographically determined in hydroalcoholic leaf extracts. All tested elderberry leaf extracts showed antioxidant effects, but the most promising potential: very high compounds content (TPC = 61.85 mg GAE/g), antioxidant (e.g., DPPH IC50 = 1.88 mg/mL; CUPRAC IC0.5 = 0.63 mg/mL) and optimal anti-inflammatory (inhibition of hyaluronidase activity 41.28%) activities were indicated for older leaves of the "Sampo" variety. Additionally, the extract obtained from "Sampo" and "Golden hybrid" variety facilitated the treatment of wounds in the scratch test. In summary, the best multidirectional pro-health effect in treating skin inflammation was specified for "Sampo" leaves II extract (leaves during the flowering period); however, wound treatment was noted as rich in chlorogenic acid younger leaf extracts of the "Golden hybrid" variety.

New record of Distimake ternifoliolus (Pittier) A.R.Simões & Staples (Convolvulaceae Juss.) from the Brazilian savanna reveals its disjunct distribution pattern

We present the first record of Distimake ternifoliolus (Pittier) A.R.Simões & Staples (Convolvulaceae) from the Brazilian savanna (Cerrado). This is a rare species, previously known only from the savannas of the Venezuelan Llanos and the Guianas. We provide a key characters, data on geographic distribution, habitat, conservation status, flowering and fruiting period, updated distribution maps and a key for Distimake Raf. species from Ceará.

Impact of a heterogeneous environment on the population expansion of the harmful plant Iris ruthenica Ker-Gawl. in the high mountain grasslands.

Iris ruthenica Ker-Gawl. (Russian iris) is a perennial, clonal, herbaceous plant that is spread across the degraded mountain grasslands in northern Xinjiang. In this study, to explore the breeding system and the impact of slope orientation on the flowering phenology, pollination characteristics, and other aspects of I. ruthenica, we used a combination of field observations and controlled experiments to compare the population density, flowering phenology, floral characteristics, breeding system, and pollinator type and behavior of plants on different slope orientations. Vegetation coverage on the north (N), southwest (SW), and southeast (SE) slopes was 90%, 67%, and 53%, respectively. Differences in plant height and diameter were observed between the SE slope and the N and SW slopes, whereas the N and SW slopes were similar in these respects. The SE slope exhibited the earliest initial flowering time, followed by the SW and N slopes. The diameter of the corolla, distance between the stigma and anther, length of the anther and ovary, number of pollen grains, and number of ovules on the N slope were smaller than those on the SE and SW slopes, whereas those of the SE and SW slopes were similar. Artificial pollination experiments showed that neither bagging nor unbagging resulted in seed formation after emasculation for all slope orientations. The pollinating insects of I. ruthenica included Bombus sp., Amegilla leptocoma, Andrena sp., and Halictus sp.; the types and numbers of pollinating insects differed among slopes. In summary, on SE and SW slopes with high temperatures and sufficient sunlight, this species attracted pollinators and provided them with more opportunities to visit and pollinate by flowering early, with large numbers of blooms, and a longer flowering period and lifespan, ensuring successful reproduction. Under unfavorable conditions, such as insufficient pollinators and limited activity caused by the more stressful environmental conditions of the N slope (including low temperature and insufficient light), this species ensures a certain seed yield by increasing its self-compatibility.

Response of rhizosphere microbial community structure and production performance of corn and soybean to belt planting mode

Soybean and corn strip cropping takes full advantage of the root characteristics and plant height differences between soybean and corn, which can improve crop photosynthesis and nutrient uptake as well as capitalize on the marginal effect of corn. However, there is not enough in-depth research on the effects of soybean and corn strip cropping modes on inter-root microbial communities and crop yield traits and their correlations, and the functional genes of inter-root microbes. In this study, the structural composition and functional genes of soil inter-root microbial communities under different strip cropping patterns of soybean and maize, Mode 1, Mode 2, and Mode 3, were studied using macro-genome high-throughput sequencing, and the yield traits of soybean and maize were determined and the correlation was understood, taking Zhonglian Soybean 1505 and Tiyu 108 maize as test materials at the experimental base of the Research Institute of Agricultural and Livestock Sciences, Xing'anmeng, Inner Mongolia. correlation between the two. The following results were found. Redundancy analysis found that rhizosphere microorganisms are mainly bacteria, followed by viruses, followed by archaea, and fungi are the least. Relatively speaking, viruses and bacteria are more susceptible to the influence of planting patterns than fungi. Alpha diversity analysis shows that the diversity index changes significantly during the peak flowering period. There is no difference between the other two stages. The diversity of maize rhizosphere microorganisms under Mode 1 or Mode 2 modes is higher than that under Mode 3 modes, while the diversity of soybean rhizosphere microorganisms under Mode 3 modes is higher than the other two modes. Profiling analysis found that different growth periods and planting patterns lead to varying degrees of changes in community structure. The dominant bacterial phyla include Pseudomonas, Actinobacteria, Bacteroidetes, and Streptococcus. The dominant genera of bacteria are rhizobia, pseudomonas, erythrobacteria, and pseudomonas. The relative abundance of slow root rhizobia in the three growth stages of maize rhizosphere is relatively low. The results of yield traits showed that corn yield under Mode 1 and Mode 2 planting was significantly higher than that under pattern III; soybean yield under pattern III planting was significantly higher than that under the other two patterns, indicating that pattern I or II planting is suitable for corn production, while Mode 3 planting mode is more suitable for soybean production. Correlation analysis showed that S_Massilis_putida was significantly and positively correlated with maize yield, and S_lysobacter_capsici was highly significantly and significantly positively correlated with the number of soybean plants per square meter, and the number of plants in 2 square meters. This study contributes to our further understanding of the classification of inter-root microorganisms and their functional relationships in maize and soybean under different conditions.

Influences of elevational gradient on flower size and number of Gentiana lawrencei var. farreri.

Plants can adapt to environmental changes by adjusting their functional traits and biomass allocation. The size and number of flowers are functional traits related to plant reproduction. Life history theory predicts that there is a trade-off between flower size and number, and the trade-off can potentially explain the adaptability of plants. Elevation gradients in mountains provide a unique opportunity to test how plants will respond to climate change. In this study, we tried to better explain the adaptability of the alpine plant Gentiana lawrencei var. farreri in response to climate change. We measured the flower size and number, individual size, and reproductive allocation of G. lawrencei var. farreri during the flowering period along an elevation gradient from 3200 to 4000 m, and explored their relationships using linear mixed-effect models and the structural equation model. We found that with elevation increasing, individual size and flower number decreased and flower size increased, while reproductive allocation remained unchanged. Individual size positively affected flower number, but was not related to flower size; reproductive allocation positively affected flower size, but was not related to flower number; there is a clear trade-off between flower size and number. We also found that elevation decreased flower number indirectly via directly reducing individual size. In sum, this study suggests that G. lawrencei var. farreri can adapt to alpine environments by the synergies or trade-offs among individual size, reproductive allocation, flower size, and flower number. This study increases our understanding of the adaptation mechanisms of alpine plants to climate change in alpine environments.

Developmental patterns of flowers and pods and the effect on seed number in French serradella (Ornithopus sativus) and yellow serradella (Ornithopus compressus) cultivars

Context Reliable seed production is a key requirement for successful year-on-year regeneration of annual pasture legumes. Aims The study aims were to investigate the developmental patterns of flowers and pods and the effect on seed number among cultivars of French (Ornithopus sativus Brot.) and yellow serradella (O. compressus L.); and to assess the effects of early flower loss. Methods Four cultivars of each species were grown in a glasshouse under non-limiting growth conditions. Date of flowering and numbers of flowers, pods and seeds were assessed for up to 20 reproductive nodes on two stem axes per plant (n = 5 plants). A flower removal treatment was imposed to assess whether early flower loss affected flower and/or pod production. Key results Flowering in the serradellas was indeterminate, but for all cultivars there was a peak period of flower and pod production, with the timing and duration of the peak period differing among cultivars. Peak flowering occurred primarily because the proportion of plants flowering began to decline, but the number of flowers per reproductive node and the number of pods formed per node also declined with time. Compensation for early flower loss was observed for most cultivars because of a longer duration of pod formation and/or greater numbers of pods developed on higher reproductive nodes. Conclusions This study demonstrated that there is diversity in the patterns of flowering and podding and number of seeds initiated among serradellas. Implications Diversity in flowering and podding patterns combined with a capacity to compensate for early flower loss may be used to develop serradellas better able to cope with environmental stressors (frost, drought, heat) experienced during the flowering window.

Понятийно-терминологический аспект практики откровения помыслов в традиции египетского и палестинского монашества IV — VII вв.

The article analyzes the original terminology of the patristic writings of Egyptian and Palestinian monasticism of the 4th - 7th centuries, which is found when mentioning the practice of revelation of thoughts as an important pastoral-ascetic activity and a form of spiritual leadership in the monastic tradition of this period. The author identifies the main terms related to this area, analyzes the context of their use and various semantic shades that reflect the corresponding forms, conditions and characteristics of this activity. Modern patrolologists strictly distinguish the practice of revealing thoughts from confession, which in ancient times was carried out in all forms of monastic life: hermitage, semi-hermitage, community and laura. At the same time, the most ancient sources do not always reflect this difference, their external forms and ideological content. Another equally important question remains not entirely clear: how the great fathers of ancient Eastern monasticism understood this saving remedy, whether for them there was a division between confession and revelation of thoughts as between two different actions of repentance, and if so, what appeared for them clear criteria for such division. The sources for the study were the most famous and significant works of monastic writing in the tradition of Egypt and Palestine in the 4th - 7th centuries, as the period of formation, development and greatest flowering of monasticism, and at the same time its ascetic and pastoral theology. Some manuscripts of individual sources were also used as sources, including the most ancient ones, reflecting the understanding of the practice being studied in the minds of scribes belonging to various manuscript traditions - Greek, Latin and Coptic. The subject of study are terms denoting revelation (of hidden thoughts, sinful falls committed in secret), revelation (of oneself, one’s emotional experiences, demonic temptations, etc.), confession (of sins, a passionate disposition of the soul and its destructive consequences), etc.

Self-(in)compatibility in Tunisian apple accessions [Malus domestica. Borkh]: S-genotypes identification and pollen tube growth analysis.

Self-incompatibility studies have revealed a potential use of Tunisian apple resources for crop improvement and modern breeding programs and a likely correlation between the pollen tube growth and flowering period. Apples [Malus domestica. Borkh] exhibit an S-RNase-based gametophytic self-incompatibility (GSI) system. Four primer combinations were used to S-genotype eighteen Tunisian local apple accessions and twelve introduced accessions that served as references. Within the Tunisian local accessions, S2, S3, S7, and S28 S-alleles were the most frequent and were assigned to 14 S-genotypes; among them, S7S28, S3S7, S2S5, and S2S3 were the most abundant. PCA plot showed that population structuring was affected by the S-alleles frequencies and revealed a modern origin of the Tunisian varieties rather than being ancient ones. Nonetheless, the results obtained with 17 SSR markers showed a separate grouping of local Tunisian accessions that calls into question the hypothesis discussed. Pollination experiments showed that the pollen started to germinate within 24h of pollination but 48h after pollination in the "El Fessi" accession. The first pollen tubes arrived in the styles within 36h of pollination in two early flowering accessions known as "Arbi" and "Bokri", and after 72h of pollination in late flowering "El Fessi" and 48h after pollination in remaining accessions. The first pollen tube arrests were observed in accessions "Arbi" and "Bokri" within 84h of pollination, within 108h of pollination in "El Fessi" and within 108h of pollination in remaining accessions. In the apple accession called "Boutabgaya," the pollen tubes reached the base of the style within 120h of pollination without being aborted. Nevertheless, the self-compatible nature of "Boutabgaya" needs more studies to be confirmed. However, our results revealed the malfunction of the female component of the GSI in this accession. To conclude, this work paved the path for further studies to enhance the insight (i) into the relation between the flowering period and the pollen tube growth, (ii) self-compatible nature of "Boutabgaya", and (iii) the origin of the Tunisian apple.

Slight drought during flowering period can improve Tartary buckwheat yield by regulating carbon and nitrogen metabolism.

This study aimed to clarify the effects of drought during flowering period on the carbon and nitrogen metabolism, growth, and yield of Tartary buckwheat. Tartary buckwheat cultivar Jinqiao 2 was treated with well-watered (CK), slight soil-drought stress (LD), moderate soil-drought stress (MD), and severe soil-drought stress (SD), with the soil water potential maintained at - 0.02 to - 0.03, - 0.04 to - 0.05, - 0.05 to - 0.06, and - 0.06 to - 0.07MPa, respectively. With prolonged growth period and an increase in drought stress, the antioxidant enzyme activities and the contents of substances and activities of enzymes related to carbon and nitrogen metabolism in Tartary buckwheat leaves initially increased and then decreased. Meanwhile, the contents of malondialdehyde and superoxide anion showed a continuous. LD treatment induced the highest antioxidant enzyme activities and the contents of substances and activities of enzymes related to carbon and nitrogen metabolism but the lowest contents of malondialdehyde and superoxide anion in Tartary buckwheat leaves. Compared with CK, LD treatment increased the grain number, 1000-grain weight (MTS), and yield per plant by 6.52%, 17.37%, and 12.35%, respectively. In summary, LD treatment can increase the antioxidant enzyme activities and the contents of substances and activities of enzymes related to carbon and nitrogen metabolism, thus enhancing the adaptability of Tartary buckwheat to drought stress and increasing the yield per plant.

Respons Tiga Varietas Tomat (Lycopersicum esculentum Mill.) Akibat Cekaman Kekeringan

Drought is one of the factors in tomato (Lycopersicum esculentu Mill.) crop failure which is often found in Indonesia. Planting drought-resistant varieties is a solution to increase the productivity of tomato to meet market demand. The research was carried out in the Kumendung Hamlet Plastic House, Ngembung Village, Cerme District, Gresik Regency at an altitude of 4 meters above sea level with an average temperature of around 25º - 34º C. This research was conducted using a factorial of Completely Randomized Design (CRD). The first factor is application water volume with 3 levels, namely: C0 = water content 100% field capacity (control); C1 = water content 75% field capacity; C2 = water content 50% field capacity. The second factor is tomato varieties with 3 levels, namely: V1 = Servo Variety; V2 = Tymoti variety; V3 = Tantyna variety. The research data were analyzed using Analysis of Variance (ANOVA), then the Least Significant Difference (LSD) test was carried out at a test level of 5%. The results showed that it was no interaction between the application of water volume and the tomato varieties. Applying water 828,75 ml or 75% of field capacity and using the Tymoti tomato variety gave the best results in terms of number of leaves, number of flowers, number of fruit, and fruit weight per plant. The Tymoti tomato variety gave the shortest flowering period. Key Words: Drought, tomatoes, varieties, watering

Phenological observations on the growth and development of saffron (Crocus sativus L.) in the conditions of the Right-Bank Forest-Steppe of Ukraine

There is a need to summarise information using phenological models to develop a sustainable saffron production technology with further regulation of flowering at a certain phenological stage and determination of the appropriate flowering period to improve yield and quality under different environmental conditions. The purpose of the study is to establish the course of phenological phases of saffron growth and development in the conditions of the Right-Bank Forest-Steppe of Ukraine. Phenological observations and biometric measurements were performed in the study. According to field observations, there are a total of 6 phenological stages of saffron development. The rest period lasts from the third ten days of May to October and is divided into primary and secondary dormancy. During the primary dormant period, corms do not show external morphological changes and growth, but internal physiological and morphogenetic changes occur. In the secondary dormant period, the initial emergence of leaves and flowers and their differentiation take place. During the dormant period, saffron plants were left without aboveground organs. The flowering period falls in October. The passage of this phenological stage may be affected by changes in environmental conditions or agricultural technology. The growth of the root system began with the appearance of flowers and leaves. During the growing season, the growth of the leaf apparatus and the development of the root system continue. During this period, daughter corms are also formed from the buds of the mother corm. During the winter, the replacement corms continue to grow using the nutrient reserves of the mother corm. In early March, the development of the root system slows down and the daughter corms reach almost the final size. At the end of the growing season, the root system of the mother corm stops growing. The leaves begin to age from the top to the base. By the end of May, the daughter corms are fully developed and are preparing for the transition to a dormant state. The number of corms produced per unit area depends on the age of the plot, nutrient supply, and the level of agricultural technology. Older fields produce more corms. Due to the higher density, a larger yield of stamens is formed. Therefore, understanding the phenological reactions and influence of climatic factors on the stages of saffron growth and development in certain soil and climatic conditions is useful for future forecasting of harvest time