Floral Bud Stage Research Articles

An Analysis of the Potential Regulatory Mechanisms of Sophora Flower Development and Nutritional Component Formation Using RNA Sequencing

Sophora flower (Huaihua) is the flower of Sophora japonica L., which is used in ethnic food and traditional medicine in China. Unfortunately, the molecular mechanism related to the nutritional quality and regulation of floral organ development has yet to be elucidated in Huaihua. To understand the molecular mechanism of the different developmental stages of Huaihua, this study evaluated the transcriptome analyses of five different developmental periods from Huaihua. A total of 84,699 unigenes were reassembled from approximate 50 million high-quality clean reads. The results showed that the phenylpropanoid biosynthesis, plant hormone signal transduction, starch and sucrose metabolism, and fatty acid elongation process pathways were strongly induced at different developmental stage genes in Huaihua. During this study, 394 differentially expressed genes (DEGs) were identified for further studies, which included 13 phenylpropanoid biosynthesis-related genes, 186 plant hormone signal transduction-related genes, and 195 starch and sucrose metabolism response genes. Regarding the peroxidase in the lignin synthesis pathway, CCoAOMT was significantly upregulated with the development of Huaihua. The enzyme genes in flavonoid synthesis, such as PAL, 4CL, flavonol reductase, and 3 GT, were significantly downregulated during Huaihua development. In addition, the results also indicated that the enrichment key genes in these pathways of Huaihua can be divided into two distinct parts at developmental stages. In the floral bud stage, flavonoid, auxin, and cytokine synthesis-related genes were highly expressed. In the mature bud and full flowering stage, the expression level of genes related to lignin, gibberellin, abscisic acid, and salicylic acid synthesis was high, while, for other genes related to flavonoid synthesis, it was lower. Furthermore, the DEGs in the starch and sucrose metabolism pathway were also significantly upregulated in the later stage of flower development. This study provides a preliminary and comprehensive assessment of the quality formation and flowering regulation mechanism in Sophora japonica L. by investigating the expression profiles of the critical flowering-related genes at different developmental stages. The results indicate that the regulatory genes in these key biological pathways could be crucial factors involved in Huaihua development, which can provide a reference and new insights with which to further understand the molecular mechanisms of flower development in Sophora japonica L.

Response of early-cycle common bean cultivars with carioca, black and speckled grains to top-dressing nitrogen fertilization

The aim was to evaluate the agronomic and qualitative attributes of early-cycle common bean cultivars with different grains types grains in response to top-dressing nitrogen (N) doses. The experiment was carried out using a randomized block design, in a split-plot scheme, with 4 replicates. The plots consisted of the cultivars IAC Nuance, IAC 1849 Polaco and IAC Veloz, with speckled, Carioca and black grains, respectively. The subplots were formed by N doses applied as top-dressing: 0 kg ha-1, 60 kg ha-1 (applied in the stage of third trifoliate leaf), 120 kg ha-1 (1/2 applied at third trifoliate leaf stage + 1/2 applied at the floral bud stage) and 180 kg ha-1 (1/3 applied at the first trifoliate leaf stage + 1/3 applied at the third trifoliate leaf stage + 1/3 applied at the floral bud stage). IAC Veloz stood out for grain yield, showing the highest grain yield in the lowest N doses, being classified as efficient to the use of N. The cultivars IAC Nuance and IAC 1849 Polaco reached maximum yields with 155 and 163 kg ha-1 of N. The IAC Nuance was the most responsive, increasing grain yield by up to 25.3% due to nitrogen fertilization. Increasing N doses applied as top-dressing increased the sieve yield and crude protein content of the common bean cultivars, with IAC Nuance standing out. The cultivars showed good grain quality, and IAC 1849 Polaco and IAC Veloz had the shortest cooking time and IAC Veloz also had the fastest hydration.

High temperatures during late floral bud stages decrease fertilization in strawberry (Fragaria × ananassa): pollen-pistil interaction and anatomical evidences

High temperature (HT) effects on pistil tissues and female gametophyte have been scarcely investigated in crops species. HT in strawberry can induce fruit malformations due to poor pollen performance in pistils, reducing the fertilization level. In this study, Fragaria × ananassa cvs. Earlibrite and Fortuna were exposed to ambient temperature (AT) or HT at late flower bud development over the duration of 3 or 5 days. To evaluate the capacity of heated apical and basal pistils to support and guide pollen tubes, we examined the performance of unheated pollen grains and their path along the pistil, as well as the anatomy of reproductive tissues. HT significantly induced a decrease in the number of adhered and germinated pollen grains and of pollen tubes in the style and the ovule micropyle. Microscopic observations revealed loss of stigmatic papillae turgidity and fertilization failures due to abnormal pollen tube paths. The latter finding was related to the high incidence of immature female gametophytes in apical pistils and unviable female gametophytes in basal pistils. Facultative apomixis is also described. This is the first report of impaired pistil functions when strawberry buds are exposed to HT, as revealed by in vivo poor pollen performance 24 h after pollination.

Changes of Essential Oil Compositions and Biological Activities of Different Phenological Stage and Part of Ducrosia anethifolia (DC.) Boiss

Ducrosia anethifolia L., an aromatic plant of the Apiaceae family, is traditionally used in Iran to improve the odor of foods and drinks. Different biological activities have been reported for this plant such as antibacterial, cytotoxic, antiproliferative, antianxiety, and sedative. The essential oil profile of D. anethifolia was investigated in different plant situations (phenological stages, stalks and fresh aerial parts in seed stage, and powdered and non-powdered seeds in 2018 and 2019). The essential oil was isolated by hydro-distillation using a Clevenger apparatus and was analyzed by gas chromatography. Decanal was the main compound of essential oil in floral-budding stage (40.26%). However, through plant growth and development, its amount decreased and the amount of 2-dodecenal-E increased (up to 64.51% in fresh seed stages). In the seeds, chrysanthenyl acetate was the major ingredient of the essential oil (49.11%), especially in aged and powdered seeds. The maximum and minimum essential oil content (w/v) was obtained from powdered seeds of 2019 (1.95%) and floral-budding stage (0.34%), respectively. Interestingly, principle component analyses (PCA) based on 15 main combinations of the essential oil scattered the studied samples in ordered arrangement from the floral-budding stage to the aged seeds. Briefly, obvious fluctuations were observed in the essential oil of D. anethifolia under various circumstances; flavorous decanal in floral budding, anticonvulsant 2-dodecenal-E in stems, and sedative chrysanthenyl acetate in powdered seeds. It seems this overlooked plant is proving worthy as a new nutraceutical, in any situations.

Pattern formation in Passiflora incarnata: An activator-inhibitor model

Based on a careful examination of the onset of violet colored dots along the filaments in the developing floral bud stage and the formation of alternating bands of violet and white color in the matured flowers of Passiflora incarnata (Passion flower), it is concluded that the pattern arises from a competition between the production of violet colored anthocyanin and the colorless flavonols along the filaments. The activator-inhibitor model of Gierer and Meinhardt along with the reaction diffusion theory of Turing is used to explain the formation of concentric rings in the flower.

Metabolic profiling and antioxidant activity during flower development in Agastache rugosa.

The online version contains supplementary material available at (10.1007/s12298-021-00945-z).

Full-length transcriptome analysis reveals the differences between floral buds of recessive genic male-sterile line (RMS3185A) and fertile line (RMS3185B) of cabbage.

Starch and sucrose metabolism and plant-pathogen interaction pathways play a dominate role in recessive genic male sterility (RGMS) of cabbage (Brassica oleracea L. var. capitata). RGMS is common in plants and has been widely applied as an effective and economic system for hybrid seed production in many crops. However, little is known regarding the molecular mechanisms of RGMS in cabbage. Hence, full-length transcriptomic and physiological analysis were performed in the spontaneous RGMS mutant RMS3185A and its near-isogenic fertile line (NIL) RMS3185B of small (< 1.6mm in diameter), medium (~ 2.5mm in diameter), and large floral buds (~ 3.4mm in diameter) to identify the differentially expressed genes (DEGs) associated with RMGS. The pollen abnormalities between RMS3185B and RMS3185A appeared at the large floral bud stage. In contrast with RMS3185B, the mature anthers and stamens of RMS3185A were shorter than those of RMS3185B, and the anthers did not dehiscent. The concentrations of glucose, fructose, trehalose, starch, and cellulose in RMS3185A were all significantly lower than those in large floral buds of RMS3185B. PacBio sequencing results showed that DEGs were mainly concentrated in large floral bud stage. In combination with the KEGG enrichment analysis of DEGs in GO terms related to cell wall, pollen and anther, pentose and glucuronate interconversions (ko00040), starch and sucrose metabolism (ko00500), and plant-pathogen interaction (ko04626) were significantly enriched. Among which, cell-wall/pectin-related genes of eighteen PEI, twenty-two PEL, three PG, and fifteen PGL involved in ko00040, and one UGDH, one SPS, four CWINV, four TPP/TPS, and four EGL involved in ko00500, as well as plant-pathogen interaction genes, including sixteen calcium-dependent protein kinase (CDPK), one cyclic nucleotide-gated ion channel (CNGC), and twenty-three calcium-binding protein CML (CML), were significantly down-regulated in RMS3185A relative to that in RMS3185B. Besides, genes involved in ko04626, including two CML and one transcription factor WRKY33, were up-regulated in RMS3185A relative to that in RMS3185B. In conclusion, we hypothesized that the expression alterations of these genes were responsible for calcium signaling and sugar metabolism, thus affecting the occurrence of RGMS in cabbage.

How do essential oil composition and phenolic acid profile of Heracleum persicum fluctuate at different phenological stages?

Heracleum persicum, commonly named Persian hogweed, is a principal native medicinal plant in Iran. Collecting H. persicum at the most appropriate growing stage is the key factor to achieve the high phytochemical quality to meet consumer's needs. In the present experiment, the aerial parts of this plant were harvested at up to six different developmental stages during the growing season to determine the phytochemical profiles. Our results indicated that the highest essential oil content was obtained in the mid‐mature seed stage (3.5%). The most elevated extract content was recorded in the floral budding stage (10.4%). In the vegetative stage, limonene (18.1%), in floral budding stage, caryophyllene (14.1%), anethole (14.6%), and β‐bisabolene (12.7%), in the full flowering stage, myristicin (15.0%), and hexyl butyrate (9.1%), in the early development of seeds stage, hexyl butyrate (32.1%), and octyl acetate (11.7%), in the mid‐mature seeds stage hexyl butyrate (38.8%), octyl acetate (14.5%), in the late‐mature/ripe seeds stage, hexyl butyrate (23.6%), and octyl acetate (10.5%) are recorded as the main components. The highest phenolic acids content was obtained in the floral budding stage (287.40 mg/g dried extract). The analysis of phenolic acids demonstrated cinnamic acid (8.0–225.3 mg/g extract), p‐coumaric acid (1.7–39.2 mg/g extract), p‐hydroxybenzoic acid (0.8–16.8 mg/g extract), and ferulic acid (2.4–15.8 mg/g extract) as the main phenolic acids. Cinnamic acid was found as the major phenolic compound in the vegetative stage following by floral budding, the full flowering stage, the early development of seeds, and late‐mature/ripe seeds stages. P‐coumaric acid was the most abundant phenolic compounds in the mid‐mature seeds stage. In this regard, the harvest time of H. persicum aerial parts can be selected to achieve the highest secondary metabolites of interest. The results of this study can be used as a guideline for grower to obtain the highest possible amount of desirable metabolites, beneficial in both food and pharmaceutical industries as well as their undeniable economical benefits.

Extranuptial nectaries in flowers: ants increase the reproductive success of the ant-plant Miconia tococa (Melastomataceae).

Although the production of extranuptial nectar is a common strategy of indirect defence against herbivores among tropical plants, the presence of extranuptial nectaries in reproductive structures is rare, especially in ant-plants. This is because the presence of ants in reproductive organs can generate conflicts between the partners, as ants can inhibit the activity of pollinators or even castrate their host plants. Here we evaluate the hypothesis that the ant-plant Miconia tococa produces nectar in its petals which attracts ants and affects fruit set. Floral buds were analysed using anatomical and histochemical techniques. The frequency and behaviour of floral visitors were recorded in field observations. Finally, an ant exclusion experiment was conducted to evaluate the effect of ant presence on fruit production. The petals of M. tococa have a secretory epidermis that produces sugary compounds. Nectar production occurred during the floral bud stage and attracted 17 species of non-obligate ants (i.e. have a facultative association with ant-plants). Ants foraged only on floral buds, and thus did not affect the activity of pollinators in the neighbouring open flowers. The presence of ants in the inflorescences increased fruit production by 15%. To our knowledge, the production of extranuptial nectar in the reproductive structures of a myrmecophyte is very rare, with few records in the literature. Although studies show conflicts between the partners in the ant-plant interaction, ants that forage on M. tococa floral buds protect the plant against floral herbivores without affecting bee pollination.

ITRAQ-Based Proteomics Reveals that the Tomato ms1035 Gene Causes Male Sterility through Compromising Fat Acid Metabolism.

So far, over 50 spontaneous male sterile mutants of tomato have been described and most of them are categorized as genetic male sterility. To date, the mechanism of tomato genetic male sterility remained unclear. In this study, differential proteomic analysis is performed between genetic male sterile line (2-517), which carries the male sterility (ms1035 ) gene, and its wild-type (VF-11) using isobaric tags for relative and absolute quantification-based strategy. A total of 8272 proteins are quantified in the 2-517 and VF-11 lines at the floral bud and florescence stages. These proteins are involved in different cellular and metabolic processes, which express obvious functional tendencies toward the hydroxylation of the ω-carbon in fatty acids, the tricarboxylic acid cycle, the glycolytic, and pentose phosphate pathways. Based on the results, a protein network explaining the mechanisms of tomato genetic male sterility is proposed, finding the compromising fat acid metabolism may cause the male sterility. These results are confirmed by parallel reaction monitoring, quantitative Real-time PCR (qRT-PCR), and physiological assays. Taken together, these results provide new insights into the metabolic pathway of anther abortion induced by ms1035 and offer useful clues to identify the crucial proteins involved in genetic male sterility in tomato.

Transcriptome landscape of Rafflesia cantleyi floral buds reveals insights into the roles of transcription factors and phytohormones in flower development.

Rafflesia possesses unique biological features and known primarily for producing the world’s largest and existing as a single flower. However, to date, little is known about key regulators participating in Rafflesia flower development. In order to further understand the molecular mechanism that regulates Rafflesia cantleyi flower development, RNA-seq data from three developmental stages of floral bud, representing the floral organ primordia initiation, floral organ differentiation, and floral bud outgrowth, were analysed. A total of 89,890 transcripts were assembled of which up to 35% could be annotated based on homology search. Advanced transcriptome analysis using K-mean clustering on the differentially expressed genes (DEGs) was able to identify 12 expression clusters that reflect major trends and key transitional states, which correlate to specific developmental stages. Through this, comparative gene expression analysis of different floral bud stages identified various transcription factors related to flower development. The members of WRKY, NAC, bHLH, and MYB families are the most represented among the DEGs, suggesting their important function in flower development. Furthermore, pathway enrichment analysis also revealed DEGs that are involved in various phytohormone signal transduction events such as auxin and auxin transport, cytokinin and gibberellin biosynthesis. Results of this study imply that transcription factors and phytohormone signalling pathways play major role in Rafflesia floral bud development. This study provides an invaluable resource for molecular studies of the flower development process in Rafflesia and other plant species.

Molecular characterization and expression analysis reveal the roles of Cys2/His2 zinc-finger transcription factors during flower development of Brassica rapa subsp. chinensis.

Conserved motif, gene structure, expression and interaction analysis of C2H2-ZFPs in Brassica rapa, and identified types of genes may play essential roles in flower development, and BrZFP38 was proved to function in flower development by affecting pollen formation. Flower development plays a central role in determining the reproduction of higher plants, and Cys2/His2 zinc-finger proteins (C2H2-ZFPs) widely participate in the transcriptional regulation of flower development. C2H2-ZFPs with various structures are the most widespread DNA-binding transcription factors in plants. In this study, conserved protein motif and gene structures were analyzed to investigate systematically the molecular features of Brassica rapa C2H2-ZFP genes. Expression of B. rapa C2H2-ZFPs in multiple tissues showed that more than half of the family members with different types ZFs were expressed in flowers. The specific expression profiles of these C2H2-ZFPs in different B. rapa floral bud stages were further evaluated to identify their potential roles in flower development. Interaction networks were constructed in B. rapa based on the orthology of flower-related C2H2-ZFP genes in Arabidopsis. The putative cis-regulatory elements in the promoter regions of these C2H2-ZFP genes were thoroughly analyzed to elucidate their transcriptional regulation. Results showed that the orthologs of known-function flower-related C2H2-ZFP genes were conserved and differentiated in B. rapa. A C2H2-ZFP was proved to function in B. rapa flower development. Our study provides a systematic investigation of the molecular characteristics and expression profiles of C2H2-ZFPs in B. rapa and promotes further work in function and transcriptional regulation of flower development.

"Characterization of Two Oasis Luzerns (El Menea, Tamentit) at the Floral Bud and Early Flowering Stages"

The Algerian Oasis cover 63,000ha (Ziban, Oued Righ, El Oued and Ouargla, Mzab, Touat, Gourara). The oasien knew, taking into account the roughness of the climatic conditions, the scarcity of water resources, the low quality of the soils, the risks of rising salts, with great ingenuity to adopt means of production and mode of production appropriate; it is the labor of men that permits the outbreak of the Oasis

Identification, sexual dimorphism and aspects of the natural history of Sapria himalayana (Rafflesiaceae) on Vietnam\u2019s Lang Biang Plateau

BackgroundSapria is a distinctive and narrowly host-specific holoparasitic genus belonging to the Rafflesiaceae. Sapria himalayana, rare throughout its range from NE India, SW China, Thailand to Vietnam, is a little-understood species first recorded for Vietnam in 1959, and only recollected there over half a century later in February 2017. This has facilitated an assessment of its taxonomic identity and our understanding of its morphology and natural history aspects.ResultsSix populations of Sapria at Vietnam’s Tuyền Lâm Lake, and another two populations at the Nam Ban Protection Forest and the Cam Ly area were found, in an area of about 20 km in radius. Previously documented size attributes, morphological details and colour patterns allowed clear identification of the Vietnamese taxon as Sapria himalayana f. albovinosa. A full description of the species for Vietnam is provided. Past authors have distinguished the sexes by column form and structure, colour of the upper disk, details of the inner surface of the perigone tube, and presence of ovarial chambers below the column in the female. We present additional observations that male flowers consistently have more steeply held perigone lobes than females, in which the lobes were more spread out at wider angles in fully open flowers, and that males have a much lower cupule than females. The latter difference, especially, appears to be useful for quick determination of the sex even in the advanced floral bud stage. The host plant was the lianescent Tetrastigma laoticum (Vitaceae), but superficially it was not possible to ascertain the clonal relationship of neighbouring host lianas. Male and female flowers were found mixed together in the same cluster from one individual liana. Potential pollinators included Calliphorid and Stratiomyid flies observed visiting open flowers.ConclusionsOur observations have added to an increased understanding of the morphology of this highly specialized parasitic life form. More than this, we have ascertained its occurrence in Vietnam, with information made available to authorities of the Lâm Đồng Province where our studies were conducted, for the sites to be specially demarcated for conservation and carefully managed tourism use.

Transcriptome analysis and identification of genes associated with flower development in Rhododendron pulchrum Sweet (Ericaceae)

Flowering process is essential for plant development. However, the molecular mechanisms driving flower development of ornamental woody Rhododendron pulchrum Sweet are difficult to elucidate due to the lack of genomic data. In this research, high-throughput sequencing and comparative transcriptome analyses of R. pulchrum flowers collected at three key stages were performed: floral bud stage, early flowering stage, and full-flowering stage. Furthermore, expression of genes involved in flower development was also validated with quantitative real-time PCR (qRT-PCR). RNA-seq yielded 96,350,697 bp of clean reads, which were assembled into 98,610 unigenes with an average length of 717 bp. 58,279 (59.10%) unigenes could be annotated, including 324 major unigenes associated with floral development. In addition, ten modules (20,443 mRNAs) were dissected in the co-expression network. Especially, Flowering Locus (FLC) and Flowering Locus T (FT) were co-expressed. 9493 differentially expressed genes (DEGs) were scanned among three stages, and most DEGs existed between flower bud stage and early flowering stage. In particular, 79 DGEs associated with flowering process were enriched in 28 GO terms. Moreover, the expression levels of MYC2, EIN3, and ARR-B were all lowest at early flowering stage, while transcripts of MYC2, TIR1, CYCD3, COL-1, and EIN3 were all peaked at flower bud stage. Transcriptome profile presented here will benefit deep insights into molecular mechanism underlying R. pulchrum flowering process.

Biomasa y calidad nutricional de cuatro variedades de alfalfa para introducir en Pamplona, Colombia

La investigación se desarrolló en el Centro de Investigación en Sanidad Vegetal y Bioinsumos de la Universidad de Pamplona (Norte de Santander), con el objetivo de evaluar la productividad y la calidad nutricional de cuatro variedades de alfalfa (Medicago sativa L.): Cuf 101, Moapa 69, SW-8210 y SW-8718. Se adelantó un experimento con cuatro tratamientos aleatorizados con tres repeticiones, para un total de 12 unidades experimentales de 9 m2 cada una. La aplicación de correctivos y enmiendas se realizó una semana antes de la siembra, con base en el análisis de suelos. Al día 70 de la siembra se realizó un corte de emparejamiento para homogeneizar cada parcela. Las mediciones de producción de biomasa verde y calidad nutricional se determinaron en el estadio de botón floral, a los 210 días de la siembra. Se aplicaron pruebas de análisis de varianza ANOVA, no encontrándose diferencias significativas entre las variedades de alfalfa para las condiciones ambientales del municipio de Pamplona, por lo que todas pueden introducirse en este agroecosistema.

Efecto de la aplicación foliar de boro en el desarrollo fenológico y cuajado de fruto de gulupa (&lt;i&gt;Passiflora edulis&lt;/i&gt; f. &lt;i&gt;edulis&lt;/i&gt; Sims)

La gulupa es un frutal nativo producido en Colombia y exportado a diferentes mercados internacionales. Los principales problemas que afectan la producción del cultivo están relacionados con la floración y fructificación, debido a limitaciones nutricionales, como la deficiencia de boro (B). La presente investigación tuvo como objetivo, evaluar el efecto de la aplicación foliar de B en el desarrollo fenológico y cuajado del fruto en plantas de gulupa bajo condiciones de campo. El estudio se llevó a cabo en una plantación experimental del municipio de Pasca (Cundinamarca, Colombia), ubicado a 2.006 msnm. Los tratamientos correspondieron a la aplicación foliar de tres dosis de ácido bórico (0; 0,3; 0,6 y 0,9 kg ha-1) aplicados en la etapa de botón floral y cuajado del fruto, durante dos ciclos productivos. Se evaluaron la longitud de las ramas productivas, el número de entrenudos, el porcentaje de cuajado del fruto, el diámetro del fruto y la emisión de botones florales y frutos. La aplicación foliar de B en las dosis evaluadas aumentó la longitud de ramas secundarias, la emisión de botones florales y frutos, y el porcentaje de cuajado del fruto. Los mejores resultados de crecimiento en el primer y segundo ciclo se lograron con 0,3 kg ha-1; aunque el porcentaje de cuajado del fruto del tratamiento 0,6 kg ha-1 fue óptimo para el primer ciclo de producción (85,19%) seguido por 0,3 kg ha-1 para el segundo ciclo de producción (90%). Los frutos del tratamiento 0,3 kg ha-1 desarrollaron un mayor diámetro ecuatorial desde los 21 días depués de transplante (ddt), alcanzando el máximo diámetro (55,68 mm) a los 136 ddt.

Translocation of metabolites in pigeonpea (Cajanus cajan L.) under the influence of mineral nutrients

Mineral nutrient sources viz., CaCl2 (0.01% and 0.02%), KNO3 (0.5% and 1%), MgCl2 (0.1% and 0.2%) and urea (1% and 2%) were applied as foliar application to pigeonpea varieties (PAU 881 and AL 201) at green floral bud stage of inflorescence to study their effect on the level of various metabolites viz., total soluble sugars, total starch, total free amino acids and total soluble proteins in leaves and their subsequent accumulation in developing seeds. It was observed that mineral nutrients caused greater accumulation of different metabolites in developing seeds (sink) which may be attributed to enhanced translocation of these metabolites from source to sink tissues as evident from their decline in leaf tissues (source) thereby strengthening the source-sink relationship in pigeonpea. Urea application @ 2% increased accumulation of metabolites in mature seeds by 27.71 (PAU 881) and 25.25% (AL 201) in case of total soluble sugars, 11.19 (PAU 881) and 11.33%(AL 201) in case of total starch, 38.23 (PAU 881) and 39.41% (AL 201) total free amino acids and 10.72 (PAU 881) and 8.66% (AL 201) of total soluble proteins as compared to their respective controls.

Improved application of tribenuron-methyl as a chemical hybridizing agent with forchlorfenuron for rapeseed hybrid breeding

Chemicals or agents that can induce plant male sterility are considered chemical hybridizing agents (CHAs) and are quite useful for plant hybrid breeding. Tribenuron-methyl (TBM) can effectively induce male sterility in rapeseed plants. However, applications of TBM in rapeseed breeding practices have not been reported. Here, treatment with the CHA referred to as CHA-TBM, which contained 0.1–0.9 mg/L TBM, induced male sterility in all 22 tested rapeseed inbred lines. However, the highest induced male sterile rates in the tested rapeseed lines were only approximately 54–57% together with poisoned rates of approximately 36–39%, which were resulted from two treatments of CHA-TBM containing 0.5 mg/L TBM at an interval of 9 days beginning at the floral bud stage (FBS) of 2.0–3.5 mm. Such male sterile rates and poisoned rates caused by CHA-TBM indicated that TBM is not an ideal CHA for rapeseed hybrid breeding. The results of many screening experiments showed that forchlorfenuron can alleviate the toxic effects of TBM on rapeseed plants. Two treatments with the CHA referred to as CHA-TBM-FCF, which contained 0.6 mg/L TBM and 2.1 mg/L forchlorfenuron, at an interval of 9 days beginning at the FBS of 2.0–3.5 mm induced male sterility in approximately 96–98% of plants of all the 22 tested rapeseed inbred lines and poisoned only approximately 2–4% of the tested plants. The CHA-TBM-FCF treatment did not affect pistil fertility of the rapeseed plants, and had no carry-over influence on stamen fertility of the rapeseed hybrids produced with this CHA. Some rapeseed hybrids were successfully produced using CHA-TBM-FCF (e.g., Qinrong 1, Qinrong 2, Qinyou 19, Qinyou 33, Qinzayou 4 and Qinzayou 5). The hybridity values of the F1 seeds of the rapeseed hybrids produced using CHA-TBM-FCF were determined to be approximately 93–98% with the simple sequence repeat (SSR) marker techniques. Together, the results indicate that CHA-TBM-FCF containing TBM and forchlorfenuron at suitable concentrations is an ideal CHA for rapeseed hybrid breeding.

Foliar application of calcium and kinetin on soybean at reproductive stage

ABSTRACTWe characterized the pollination and fecundation times in soybean flowers and evaluated the effects of kinetin and calcium applications on physiological and productive traits of soybean plants during the reproductive stage. The anatomical study of flowers of eight soybean cultivars showed that fecundation occurred in closed flowers with visible petals, which presented embryo in the first cell divisions. These results indicate that fertilizers and growth regulation applications should be performed before flower opening, which is different from the current recommendation. Foliar applications of kinetin and calcium between the floral bud and full flowering stages did not affect carbon dioxide (CO2) assimilation, yield components and final yield. The results obtained in this research showed the lack of viability of foliar application of calcium and kinetin in order to increase pod set and number of seeds per plant in soybean crop.