Female Flowers Research Articles

Floral Scent Chemistry and Pollinators of a Sexually Dimorphic Neotropical Orchid

Catasetum is a speciose Neotropical orchid genus of which male and female flowers emit scents acting both as attractant and reward for their exclusive pollinators, male orchid bees (Euglossini: Apidae). In Catasetum, it is well known that flowers display a remarkably morphological sexual dimorphism. However, it remains poorly investigated whether this is also true for floral scents. Here, we investigated the pollination ecology and floral scent traits (chemistry and total emission) of C. maranhense, a species endemic to the Brazilian N/NE region. Males of Euglossa securigera are the only pollinators of C. maranhense. The floral scent of C. maranhense is composed of 29 volatile compounds, with eucalyptol, indole, (E)-Methyl p-methoxycinnamate, and (Z)-Methyl p-methoxycinnamate accounting for more than 80% of the scent bouquet. No sexual dimorphism was detected in any of the traits investigated. We discuss the ecological and evolutionary significance of our findings to Catasetum species and other unisexual perfume plants.

Female flowers first: QTL mapping in eastern black walnut (Juglans nigra L.) identifies a dominant locus for heterodichogamy syntenic with that in Persian walnut (J. regia L.)

Eastern black walnut (Juglans nigra L.), one of the most valuable timber and veneer trees in North America, provides nut shells with unique industrial uses and nut kernels with distinctive culinary attributes. A mature F1 full-sib progeny orchard of 248 individuals from the cross of two eastern black walnut cultivars provides a long-term resource for discovering genetic mechanisms controlling life history, quality traits, and stress resistance. The genetic linkage map, constructed with 356 single nucleotide polymorphism (SNP) markers and 62 expressed sequence tag simple sequence repeats (EST-SSRs), is 1645.7 cM in length, distributed across the expected 16 linkage groups. In this first application of QTL mapping in J. nigra, we report QTL for budbreak, peak pistillate bloom, peak staminate bloom, and heterodichogamy. A dominant major QTL for heterodichogamy is reported, the sequence for which is syntenic with the heterodichogamy QTL on chromosome 11 of Persian walnut (J. regia L.). The mapping population parents are both protogynous, and segregation suggests a Mendelian component, with a 3:1-like inheritance pattern from heterozygous parents. Mapping the sequenced EST-SSR markers to the J. regia “Chandler” V2.0 genome sequence revealed evidence for collinearity and structural changes on two of the sixteen chromosomes. The inclusion of sequenced EST-SSR markers enables the direct comparison of this and subsequent J. nigra maps and other Juglandaceae genetic maps. This investigation initiates long-term QTL detection studies for quality and stress resistance traits in black walnut.

PRODUCTION OF OIL PALM (Elaeis guineensis Jack) FLOWER BUNCHES IN ULTISOL ON APPLICATION OF BIOFERTILIZERS AND IN ORGANIC FERTILIZERS

One of the efforts to increase the production of oil palm flower bunches in ultisols is applying biofertilizers and inorganic fertilizers. Biofertilizers can reduce the use and adverse effects of inorganic fertilizers. Arbuscular Mycorrhizal Fungi (AMF) is one of the biofertilizers that can help plants absorb nutrients and increase plant resistance to various environmental stresses. This study aimed to examine the role of AMF (as biofertilizer) and inorganic fertilizers in increasing the production of oil palm flower bunches in Ultisol. This experiment is a factorial experiment using a Randomized Block Design. The first factor is the application of biofertilizers, which consists of two levels without biofertilizers (AMF) and with biofertilizers (AMF). The second factor is the dose of inorganic fertilizer, composed of 5 levels, no inorganic fertilizer, 25, 50, 75, and 100% recommended doses of inorganic fertilizer. The variables observed were the number of sheaths, the percentage of broken sheaths, the number of male flower bunches, the number of female flower bunches, the percentage of male and female flower bunches, sex ratio per plant, and AMF colonization. The results showed that AMF biofertilizer saved 25% of inorganic fertilizers and increased 29.33% of female flowers production. The highest production of oil palm flower bunches was obtained from the application of AMF biofertilizer and 75% of inorganic fertilizers (1.5 kg Urea, 1.1 kg SP-36, 1.2 kg MOP, 0.7 kg Kisserite per plant). Oil palm with AMF had a higher average sex ratio than plants without AMF biofertilizers. The average sex ratio in oil palm plants applying AMF biofertilizer and inorganic fertilizers ranged from 0.42 to 0.73.

Impacts of soil nutrition on floral traits, pollinator attraction, and fitness in cucumbers (Cucumis sativus L.)

Annual plants allocate soil nutrients to floral display and pollinator rewards to ensure pollination success in a single season. Nitrogen and phosphorus are critical soil nutrients whose levels are altered by intensive land use that may affect plants’ fitness via pollinator attractiveness through floral display and rewards. In a controlled greenhouse study, we studied in cucumbers (Cucumis sativus) how changes in soil nitrogen and phosphorus influence floral traits, including nectar and pollen reward composition. We evaluated how these traits affect bumble bee (Bombus impatiens, an important cucumber pollinator) visitation and ultimately fruit yield. While increasing nitrogen and phosphorus increased growth and floral display, excess nitrogen created an asymptotic or negative effect, which was mitigated by increasing phosphorus. Male floral traits exhibited higher plasticity in responses to changes in soil nutrients than female flowers. At 4:1 nitrogen:phosphorus ratios, male flowers presented increased nectar volume and pollen number resulting in increased bumble bee visitation. Interestingly, other pollinator rewards remained consistent across all soil treatments: male and female nectar sugar composition, female nectar volume, and pollen protein and lipid concentrations. Therefore, although cucumber pollination success was buffered in conditions of nutrient stress, highly skewed nitrogen:phosphorus soil ratios reduced plant fitness via reduced numbers of flowers and reward quantity, pollinator attraction, and ultimately yield.

Morphological Characterization and Evaluation Of Snake Gourd Genotypes for Fruit Yield, Yield Attributes and Other Characters

The experiment was conducted at the research field of Horticulture Department of Bangabandhu Sheikh Mujibur Raman Agricultural University (BSMRAU) during the period from March to June 2017 to characterize and evaluate the snake gourd genotypes morphologically. In the study, 55 snake gourd genotypes collected from Plant Genetic Resources Centre (PGRC) of Bangladesh Agricultural Research Institute (BARI), Genetics and Plant Breeding Department of BSMRAU, different seed companies and various parts of Bangladesh. The genotypes exhibited 67.3% cylindrical, 21.8% elliptical, 1.8% fusiform, 9.1% ovate shape fruit along with 56.4% green, 18.2% light green, 16.4% dark green and 9.0% white fruit. Seed colour with 38.2% was brown and 83.6% seed shape was elliptical. The fruit length varied from 12 to 54 cm while fruit diameter varied from 3.5 to 5.5 cm. Days to 1st female flower opening ranged between 44 and 62 days and nodes number on female flower initiation was between 12 and 26. Days to 1st fruit harvest varied from 54 to 72 days. The number of fruits/plants ranged from 8.33 to 27, whereas individual fruit weight varied from 90 to 325g. Fruit yield/plant ranged from 1.29 to 7.74 kg. Genotypes were TC01, TC03, TC04, TC05, TC07, TC08 and TC19 identified as early maturity. The genotypes differed significantly in most of the parameters and offer a good scope for selection of parent for crop improvement programme.
 Bangladesh J. Agril. Res. 45(4): 349-370, December 2020

Evaluation of Inbred Lines and Their Tester Hybrids and Estimation of Heterozygosity for Some Quantitative Traits in Maize

Nine inbred lines of maize were sowing :(OH, ZP- 301, unn440, Inbreed12, Zp- 607, SH, Ik-58, IK-8 and R-153). The first five was used as a tester (males) and the reminder used as line (females) during at 2014 season (spring) according to method (Line X Tester) to obtain 20 crosses, while the evaluation season was in Shiwan province / Kirkuk governorate of parents and its crosses and the commercial variety (Moring) at spring of 2015 using Random Complete Block Design (RCBD) design with three replicates. The studied traits were: (No. of days to 50% male flowering and female flowering, plant height, ear leaf area, No. of the rows ear-1, No. of the grains row-1, No. of the grains ear-1, 100 grains weight and grain yield plant-1). The most results were summarized as follows: The genotypes (parents, crosses and commercial variety) showed significant differences at 1% level probe for all studied except days to 50% female flowering for parents. Crosses gave highly (Inbred12 X IK-58) for ear leaf area (681.06 cm) and the cross (R-153 X Inbred 12) for both No. of the grains row-1 and grain yield plant-1 (760.23 grain) and (175.457gm) respectively, the cross (Ik-58 x OH) for 100 grains weight (30.387gm). The crosses (IK-58 X OH), (SH X Zp-301), (Zp-301 X Ik-8), (Ik-8 X Un-44052), (IK-8 X Inbred12), (R-153 X Inbred12) and (SH X Zp-607) gave desired significant heterosis over the better parents as well as the commercial variety for most traits included the grain yield plant-1. The parents SH, Zp-607 and Zp-301 to be used in single cross production and synthetic varieties, also the crosses (SH X OH), (SH X Un-44052), and (R-153 X Un-44052) in double cross production and compound crosses because these hybrids put in different main and secondary groups through cluster analysis.

Effect of wet or dry pollen application methods on ‘Hayward’ kiwifruit production

ABSTRACT Kiwifruit is a dioecious plant that relies on pollen transfer from male to female flowers to produce export quality fruit. Achieving sufficient pollination in commercial orchards can be challenging, and various additional pollination treatments are used, including pollination by honey bees (Apis mellifera); wet application (once) in conjunction with honey bees; dry application (once) in conjunction with honey bees; wet application (twice) in conjunction with honey bees. This study compared the effectiveness of these four pollination treatments for increasing commercial fruit yield in a ‘Hayward’ kiwifruit (Actinidia deliciosa) orchard using a strip male system. Three trials of four treatments were performed in three blocks of the orchard by taking a sample of 50 bays (0.09 hectare) for each treatment in the 2020–2021 crop year. There was no significant difference in weights of ‘Hayward’ kiwifruit between the four treatments within and across the three trials (P > 0.05). However, there were significant differences between the treatments regarding ‘class 1’ ‘Hayward’ kiwifruit production (trays/ha) across the three trials (P < 0.05). Wet application (once) with honey bees, dry application (once) with honey bees and wet application (twice) with honey bees produced 10.8%, 10.8% and 35.1% more ‘class 1’ ‘Hayward’ kiwifruit than honey bees alone, respectively.

Post-pollination sepal longevity of female flower co-regulated by energy-associated multiple pathways in dioecious spinach.

Reproductive growth is a bioenergetic process with high energy consumption. Pollination induces female flower longevity in spinach by accelerating sepal retention and development. Cellular bioenergetics involved in cellular growth is at the foundation of all developmental activities. By contrast, how pollination alter the sepal cells bioenergetics to support energy requirement and anabolic biomass accumulation for development is less well understood. To investigate pollination-induced energy-associated pathway changes in sepal tissues after pollination, we utilized RNA-sequencing to identify transcripts that were differentially expressed between unpollinated (UNP) and pollinated flower sepals at 12, 48, and 96HAP. In total, over 6756 non-redundant DEGs were identified followed by pairwise comparisons (i.e. UNP vs 12HAP, UNP vs 48HAP, and UNP vs 96HAP). KEGG enrichment showed that the central carbon metabolic pathway was significantly activated after pollination and governed by pivotal energy-associated regulation pathways such as glycolysis, the citric acid cycle, oxidative phosphorylation, photosynthesis, and pentose phosphate pathways. Co-expression networks confirmed the synergistically regulation interactions among these pathways. Gene expression changes in these pathways were not observed after fertilization at 12HAP, but started after fertilization at 48HAP, and significant changes in gene expression occurred at 96HAP when there is considerable sepal development. These results were also supported by qPCR validation. Our results suggest that multiple energy-associated pathways may play a pivotal regulatory role in post-pollination sepal longevity for developing the seed coat, and proposed an energy pathway model regulating sepal retention in spinach.

Influence of Foliar Spray of Brassinosteroids (BR), Salicylic Acid (SA) and Gibberellic Acid (GA3) on Vegetative Growth and Flowering Parameters of Cucumber (Cucumis sativus L) cv. Arpit.

An investigation entitled “Influence of foliar spray of Brassinosteroids (BR), Salicylic acid (SA) and Gibberellic acid (GA3) on vegetative and flowering parameters of Cucumber (Cucumis sativus L) cv. Arpit” was carried out at the Vegetable Research Farm, Department of Horticulture, Sam Higginbottom University of Agriculture, Technology &amp; Science, Prayagraj, (U.P.) - 211007 during the year 2018-19 and 2019-2020. The experiment was laid out in a Randomized Block Design with 15 treatments and 3 replications and each replicated thrice. Source of variables were Brassinosteroids (BR) 0.05 PPM, Brassinosteroids (BR) 0.10 PPM, Brassinosteroids (BR) 0.5 PPM, Brassinosteroids (BR) 1.0 PPM, Brassinosteroids (BR) 2.0 PPM, Salicylic acid (SA) 0.05 mM, Salicylic acid (SA) 0.10mM, Salicylic acid (SA) 0.2mM, Salicylic acid (SA) 0.5mM, Salicylic acid (SA) 1.0mM, Gibberellic acid (GA3) 25 PPM, Gibberellic acid(GA3) 50 PPM, Gibberellic acid(GA3) 100 PPM, Gibberellic acid (GA3) 150 PPM and combination of them with control treatment taken as 15 treatments. As far as the vegetative growth and flowering is concerned, application of different treatment of plant growth regulators significantly enhanced the Length of main vine (cm), Number of branches per plant, Number of leaves per plant, Diameter of main stem (cm), Inter-nodal distance (cm), Leaf area (cm2), Days to first flower bud initiate (DAS), Days taken to 50% flowering, Number of male flower per plant, Number of female flower per plant at all successive stages. The maximum vine length (143.17 and 146.04cm), number of leaves per plant (93.74 and 94.74), number of branches per plant (19.49 and 19.82), diameter of main stem (14.70 and 16.02cm), leaf area (277.42 and 280.90 cm2), internodal distance (7.27 and 6.97cm) and as per flowering parameters lowest days taken to first flower bud initiation (36.66 and 35.73 days), days taken to 50% flowering (42.40 and 422.73 days), number of male flower per plant (91.71 and 92.05) and number of female flower per plant (47.59 and 46.92) were recorded in both successive year with T5 (Brassinosteroids (BR) 2.0 PPM) and minimum growth and flowering were observed in T0 (control).

Fine‐scale temporal dynamics of flower visitors sheds light on insect‐assemblage overlap between sexes in a dioecious Ecuadorian palm

AbstractDioecious plants generally display sexual dimorphism in male and female floral traits, potentially attracting slightly different pollinator communities. The sharing of common floral visitors between male and female flowers and their timing of visits to both sexes is of critical importance to ensure plant's reproductive success. Palm inflorescences are visited by abundant and diverse insect communities, yet the temporal patterns of insect visits on both sexes remain poorly known. We characterized the composition of a community of flower‐visiting arthropods associated with the dioecious ivory palm (Phytelephas aequatorialis, Spruce) in a pre‐montane forest of Ecuador. We monitored the temporal variations in insect visits along the flowering of 12 inflorescences (eight female and four male) using interception traps recovered every 4 h. We report 59 morphospecies in the arthropod community, dominated by three beetle families: Staphylinidae, Nitidulidae, and Curculionidae. Male inflorescences were more abundantly visited than female, but visitors of the later were taxonomically more diverse. Among the 16 pollinator candidates identified, nine visited both inflorescence sexes synchronously at dusk /night whereas the others did so asynchronously during the day. Our study provides new insights into the pollination mechanism ofP. aequatorialis.We found evidence of differential pollinator attraction between floral sexes, which may be explained by the sexual dimorphism of both flowers. Synchronicity in dusk/night visits of both inflorescence sexes suggests a sexual synchronization of the signal used to attract pollinators.Abstract in Spainsh is available with online material

Two New Species of Mutualistic Gall Midges (Diptera: Cecidomyiidae) Responsible for the Pollination of Phyllanthus flexuosus (Phyllanthaceae) and Using Its Male Flower Buds as Brood-Sites

Two new species of gall midges (Diptera: Cecidomyiidae: Cecidomyiinae) associated with male flower buds of Phyllanthus flexuosus (Phyllanthaceae) are described and illustrated. Clinodiplosis gagnei Elsayed, new species, induces male flower bud galls, whereas Macrolabis katoi Elsayed, new species, is an inquiline. Females of both species visit the host plant at flowering in search of suitable oviposition sites and, in doing so, become dusted with pollen of the opened male flowers and come in contact with the stigmas of female flowers. Larvae of both gall midge species overwinter in the ground, and each has only one generation per year. This is the first report of the genus Macrolabis in Japan.

Selection of cucumber for parthenocarpy for spring greenhouses

Scientific relevance. Currently, in the protected ground, the main areas are occupied by parthenocarpic hybrids of cucumber of foreign origin. Therefore, the selection of domestic cucumber hybrids of the parthenocarpic type is very relevant.Material and conditions. The experience was laid in 2018-2022 in the Odintsovo district of the Moscow region in the conditions of a spring film ground greenhouse of the "Block" type on the basis of the head institution of the FSBSI FSVC. Agrotechnics of cultivation is generally accepted for the conditions of spring film greenhouses. In breeding nurseries where there were no bees, the degree of parthenocarpy was determined as the ratio of the fruit set to the number of female flowers formed on the plant, as a percentage. The records were carried out from the 5th to the 20th node inclusive, only on plants of the female type of flowering. On the basis of the laboratory of breeding and seed production of pumpkin crops, 27 collectible and more than 50 breeding samples of parthenocarpic cucumber were studied.Results. During three years of research, 7 hybrids of cucumber of the parthenocarpic type of foreign breeding were selected based on the sum of economically useful traits.These hybrids were distinguished by a high degree of parthenocarpy. With their participation, as a result of multiple selections and self-pollination, more than 50 breeding lines were created. Analysis of the obtained material showed that the degree of manifestation of parthenocarpy on the plant (the arithmetic mean between the indicators of parthenocarpy on the main and lateral shoots) in the best half of the samples in 2021 was in the range of 30-50%, whereas in 2022 it already reached 50-70%. The parthenocarpy severity coefficient above 70% was noted only in 2022 in 4% of samples. About half of the samples showed a fairly low parthenocarpy: in 2021 no more than 30%, and in 2022 no more than 50%. Most of them were rejected. The parthenocarpy of the best breeding samples in 2022, compared with 2021, increased by an average of 17.7%. Breeding lines obtained even from the same collection sample often differed greatly, sometimes by 4 times, in the degree of parthenocarpy. The families of the most stable parthenocarpy samples had differences on this basis in 2021 only 3-6%, and in 2022 – 10-11%. Families with the greatest severity of this trait were selected annually. It can be concluded that the degree of parthenocarpy in cucumber strongly depends on both the genotype of the sample and the growing conditions. 3 breeding lines were selected, characterized by high indicators of the degree of manifestation of parthenocarpy in 2021 (61.5-70.5%) and the stability of the manifestation of this trait by families and years.

Genome-Wide Identification of AP2/ERF Superfamily Genes in Juglans mandshurica and Expression Analysis under Cold Stress

Juglans mandshurica has strong freezing resistance, surviving temperatures as low as -40 °C, making it an important freeze tolerant germplasm resource of the genus Juglans. APETALA2/ethylene responsive factor (AP2/ERF) is a plant-specific superfamily of transcription factors that regulates plant development, growth, and the response to biotic and abiotic stress. In this study, phylogenetic analysis was used to identify 184 AP2/ERF genes in the J. mandshurica genome, which were classified into five subfamilies (JmAP2, JmRAV, JmSoloist, JmDREB, and JmERF). A significant amount of discordance was observed in the 184 AP2/ERF genes distribution of J. mandshurica throughout its 16 chromosomes. Duplication was found in 14 tandem and 122 segmental gene pairs, which indicated that duplications may be the main reason for JmAP2/ERF family expansion. Gene structural analysis revealed that 64 JmAP2/ERF genes contained introns. Gene evolution analysis among Juglandaceae revealed that J. mandshurica is separated by 14.23 and 15 Mya from Juglans regia and Carya cathayensis, respectively. Based on promoter analysis in J. mandshurica, many cis-acting elements were discovered that are related to light, hormones, tissues, and stress response processes. Proteins that may contribute to cold resistance were selected for further analysis and were used to construct a cold regulatory network based on GO annotation and JmAP2/ERF protein interaction network analysis. Expression profiling using qRT-PCR showed that 14 JmAP2/ERF genes were involved in cold resistance, and that seven and five genes were significantly upregulated under cold stress in female flower buds and phloem tissues, respectively. This study provides new light on the role of the JmAP2/ERF gene in cold stress response, paving the way for further functional validation of JmAP2/ERF TFs and their application in the genetic improvement of Juglans and other tree species.

Jasmonate-deficient mutant lox3a reveals crosstalk between jasmonate and ethylene in the differential regulation of male and female flower opening and early fruit development in Cucurbita pepo.

Jasmonate (JA) has been found to be a relevant hormone in floral development in numerous species, but its function in cucurbit floral development and sex determination is unknown. Crosstalk between JA and ethylene (ET) in the differential regulation of male and female floral development was investigated by using the novel JA-deficient mutant lox3a, and the ET-deficient and -insensitive mutants, aco1a and etr2b, respectively, of Cucurbita pepo. The lox3a mutation suppresses male and female flower opening and induces the development of parthenocarpic fruit. A bulked-segregant analysis coupled with whole genome sequencing and fine mapping approach allowed the identification of lox3a mutation in CpLOX3A, a LIPOXYGENASE gene involved in JA biosynthesis. The reduced JA content and expression of JA-signalling genes in male and female flowers of lox3a, and the rescue of lox3a phenotype by external application of methyl jasmonate (MeJA), demonstrated that JA controls petal elongation and flower opening, as well as fruit abortion in the absence of fertilization. JA also rescued the phenotype of ET mutants aco1a and etr2b, which are both specifically defective in female flower opening and fruit abortion. ET, the sex determining hormone of cucurbits, is induced in female flowers towards anthesis, activating JA production and promoting the aperture of the female flower, and the abortion of the unfertilized ovary. Given the close association between flower closure and parthenocarpic fruit development, we propose that flower opening can act as a switch that triggers fruit set and development in fertilized ovaries, but may alternatively induce the abortion of the unfertilized ovary. Both ET and JA from mature and senescent petals can serve as remote signals that determine the alternative development of the ovary and fruit.

Geranium sylvaticum increases pollination probability by sexually dimorphic flowers.

Sexual dimorphism is expressed as different morphologies between the sexes of a species. Dimorphism is pronounced in gynodioecious populations which consist of female and hermaphrodite individuals. The small size of female flowers in gynodioecious species is often explained by resource re-allocation to seed production instead of large flowers. However, pollinator attraction is critical to female fitness, and factors other than resource savings are needed to explain the small size of female flowers. We hypothesized that the floral size dimorphism in the perennial gynodioecious Geranium sylvaticum (L.) is adaptive in terms of pollination. To test this "pollination hypothesis," we video recorded the small female and large hermaphrodite G.sylvaticum flowers. We parameterized floral visitor behavior when visiting a flower and calculated pollination probabilities by a floral visitor as the probability of touching anther and stigma with the same body part. Pollination probability differed in terms of flower sex and pollinator species. Bumblebees had the highest pollination probability. The small female flowers were more likely to receive pollen via several pollinator groups than the large hermaphrodite flowers. The pollen display of hermaphrodites matched poorly with the stigma display of hermaphrodites, but well with that of females. Although the small size of female flowers is commonly explained by resource re-allocation, we show that sexual dimorphism in flower size may increase the main reproductive functions of the females and hermaphrodites. Dimorphism increases pollination probability in females and fathering probability of the hermaphrodites likely driving G.sylvaticum populations towards dioecy.

Development of Hermaphrodite Salacca (Salacca zalacca) SNAP Marker: A Novel Conservation Tool

Salacca (Salacca zalacca) or snake fruit is a tropical fruit, which is considered to be originated from Indonesia. One of the challenges in salacca conservation is the wide genetic diversity of the plants due to their natural cross-breeding. Most S. zalacca are dioecious plants by having fertile female and male flowers on different individuals, except for Salak Bali which is regarded to be monoecious. Morphological and cytogenetic markers have failed to differentiate the salacca plants’ sex types during the vegetative phase, thus the molecular marker is an alternative. We explored the specific salacca gene sequence on various sex types of salacca plants to identify sex-related single nucleotide polymorphism. The SNAP markers were then developed using the chosen SNP and validated on a total of 30 salacca samples. Nine samples of salacca’s female, male, and hermaphrodites were amplified using designed primers. The produced bands were sequenced and analyzed using Geneious Prime software. The analysis implied 9 SNPs on the 446 bp of salacca’s specific partial sequences. The SNAP markers were designed based on SNP validation showed that the marker potentially used a hermaphrodite-specific marker. The development of molecular markers as an early salacca sex type detection tool may be helpful in fruit cultivation, accelerating the plant breeding program, as well as on conservation management.

Physiological Responses and Identification of Drought- Responsive miRNAs in Oil Palm Seedlings under Drought Stress ConditionsResilient Forests

Global climatic change poses a considerable risk to Malaysia’s booming oil palm industry as theinflorescence initiation and differentiation in oil palms are affected by drought stress. As a result, theproportion of female flowers significantly decreases, leading to reduced fruit bunch productivity. Hence, itis crucial for plantation companies to understand the physiological response of different oil palm genotypesto drought stress in ensuring that suitable genotypes are selected for stable yield production. Therefore, thisstudy aimed to understand the physiological and biochemical responses of oil palm seedlings under droughtstress conditions and to identify drought-responsive miRNAs in different oil palm progenies. Drought stresstreatment was imposed on 3-month-old seedlings consisting of two oil palm genotypes, Deli dura x pisifera(BC21) and URT-Calabar (EB8), by withholding irrigation for 20 days. Physiological measurements suchas fluorescence parameter (Fv/Fm) and stomatal conductance (gs) were then carried out weekly. Biochemicalassays were also performed to measure the chlorophyll content and proline concentration. Finally, advancedmolecular techniques were conducted to identify drought-responsive miRNA from drought stress samples.Based on the results, the decreased soil volumetric water content (vwc) resulted in a reduced plant growthrate with low biomass in drought stress BC21T (37%) and EB8T (31%). In addition, the increased prolinecontent in both genotypes by 3.9-fold for BC21T and 1.8-fold for EB8T confirmed the stress condition intreated seedlings. Furthermore, significant differences in gs and Fv/Fm were recorded earlier in BC21 (6days, 14 days) compared to EB8 (14 days, 20 days). The earlier gs reduction indicated that BC21 was moresensitive to drought stress than EB8. Meanwhile, bioinformatics analysis of small RNA sequencing readsidentified 151 conserved miRNAs in both genotypes, with 58 out of 77 identified as novel miRNAs weredifferentially expressed. Apart from that, nine miRNAs were identified as responsive to drought treatmentin both genotypes and played an essential role in various biological processes. Overall, this study providesvaluable insights into exploring oil palm physiological responses to drought and miRNA expressionpatterns, which may facilitate future research on developing drought tolerant markers.

Character Association and Path Coefficient Studies in Cucumber (Cucumis sativus L.): Experimental Investigation

Thirty two cucumber genotypes were collected from different states of India and were evaluated for yield and quality characters at Bhubaneswar, Odisha during Rabi season of 2019. The relationships between fruit yield and yield components in cucumber genotypes were investigated and correlation studies revealed that yield per plant had positive and significant association with vine length, number of fruits per plant, fruit length, fruit diameter and average fruit weight, while significant negative correlations were observed with node at which first female flower appears, number of days to first female flower production, days to first harvest and severity of downy mildew percentage both at phenotypic and genotypic levels. Path coefficient analysis revealed that fruit diameter had maximum positive direct effect on yield per plant followed by fruit length, number of fruits per plant, days to first harvest, average fruit weight while, negative direct effect of number of days to first female flower production and severity of downy mildew percentage was observed on yield per plant. Future breeding should focus on selecting the characters having direct effects to improve yield per plant.

Effect of Cropping Systems and Integrated Nutrient Management on Growth and Yield of Coconut in Littoral Sand

An experiment was carried out in a 38 years old coconut plantation of Sakhigopal Local Tall variety at All India Coordinated Research Project on palms, Konark (OUAT) during July 2017 to June 2019. The treatments comprised of three cropping system and three integrated nutrient management practices. The experiment was laid out in a Split Plot Design with three replications. The studies revealed that adoption of cropping system of coconut + sapota + pineapple with application of green manuring + biofertilizers + organic recycling + soil test based nutrients NPK (chemical fertilizers) application significantly increase the number of female flowers (245.83/palm/year), nut yield (65.21/palms/year), weight of whole nut (1206.54 g), weight of dehusked nut (603.01 g), kernel weight (293.41 g) and copra weight (168.33 g). Similarly minimum number of female flowers, nut yield, kernel weight and copra weight were recorded in treatment combination of monocrop of coconut with green manuring + biofertilizers + organic recycling. The study indicated that cropping coconut + sapota + pineapple cropping system with organic and soil test based nutrients NPK are suitable for better growth and development of coconut.

Ceriscoides glabra (Gardenieae: Rubiaceae), a new species from Kon Chu Rang Nature Reserve, southern Vietnam

Ceriscoides glabra, a new species of the tribe Gardenieae (Rubiaceae), is described and illustrated. The species was discovered in 2017–2018 in Kon Chu Rang Nature Reserve (Gia Lai Province, southern Vietnam), in the vicinity of the locally well-known K50 waterfall, also known as Hang En waterfall. The new species differs from its congeners by the following features: plant entirely glabrous, leaf blade mostly less than 6.5 cm long and less than 4 cm wide, with 3–4 pairs of secondary veins and without domatia, calyx in female flowers glabrous with lobes more than 9 mm long, and corolla lobes in female flowers more than 10 mm long and distinctly longer than wide.