Flower development and sexual dimorphism in Vernicia montana

The mu oil tree(Vernicia montana Lour.) is a dioecious species, but the genetic mechanisms underlying its phenotypic sexual dimorphism are unclear. In this study, we determined two pivotal phases of sex differentiation of mu oil tree via morphological and histological analyses of unisexual flowers:(Ⅰ) differentiation of male or female primordia to produce staminate flowers(SFs) or transient hermaphrodite flowers(HFs),and(Ⅱ) complete abortion of stamens in transient HFs to generate pistillate flowers(PFs). A total of 1621 sex-biased genes were identified by comparative transcriptome analysis which exhibited elevated rates of protein evolution than unbiased genes. The female-biased genes were enriched in the production of defense compounds while male-biased genes were focused on the production of viable pollens. Transcriptomebased analysis revealed that the differentially expressed genes(DEGs) between PFs and SFs in phase Ⅰ involved in abscisic acid(ABA), auxin(AUX), cytokinin(CK), ethylene(ET), and gibberellin(GA) biosynthesis and signaling showed higher expression levels in males than in females in general, whereas the DEGs involved in jasmonic acid(JA) and salicylic acid(SA) pathways displayed opposite expression patterns. Moreover,differentially expressed endogenous ABA, AUX, GAs, JA, and SA exhibited consistent biased expression patterns with the DEGs by UPLC-MSbased analysis. Exogenous application of an anti-ethylene plant growth regulator could promote the development of stamens in PFs and generated HFs. Comparative transcriptomic and hormonal analyses of PFs and SFs in phase Ⅱ indicated an increase in ET concentration when abortion of stamens in PFs occurred. This study suggested that phytohormones play key roles in sex dimorphism and ET may determine the development of stamens in PFs of mu oil tree, which provides an insight into plant sex differentiation mechanisms.

Species-specific regulatory pathways of small RNAs play sophisticated roles in flower development in Dimocarpus longan Lour.

Flower development plays vital role in horticultural plants.Post-transcriptional regulation via small RNAs is important for plant flower development.To uncover post-transcriptional regulatory networks during the flower development in Dimocarpus longan Lour.‘Shixia’,an economically important fruit crop in subtropical regions,we collected and analyzed sRNA deep-sequencing datasets and degradome libraries Apart from identifying miRNAs and phased siRNA generating loci(PHAS loci),120 hairpin loci,producing abundant sRNAs,were identified by in-house protocols.Our results suggested that 56 miRNA-target pairs,2221-nt-PHAS loci,and 111 hairpin loci are involved in posttranscriptional gene silencing during longan reproductive development.Lineage-specific or species-specific post-transcriptional regulatory modules have been unveiled,including miR482-PHAS and miRN15.miR482-PHAS might be involved in longan flower development beyond their conserved roles in plant defense,and miRN15 is a novel miRNA likely associated with a hairpin locus(HPL-056)to regulate strigolactone receptor gene DWARF14(D14)and the biogenesis of phasiRNAs from D14.These small RNAs are enriched in flower buds,suggesting they are likely involved in post-transcriptional regulatory networks essential for longan flower development via the strigolactone signaling pathway.

A global view of transcriptome dynamics during flower development in Capsicum annuum L.

An analysis of genome-wide gene expression profiles during floral organ development can provide important clues about the molecular basis of gene functions and developmental processes.In this study,we analyzed the transcriptome data of 36 samples obtained during floral organ development from pepper‘6421’and detected 30016 genes that were expressed in at least one sample.K-means clustering analysis was used to classify the data into 16 clusters based on the similarities between the dynamic expression profiles of genes.Of these,15 clusters exhibited notable up-regulation or down-regulation trends in different developmental stages or tissues of floral organs.We identified transcription factors expressed at the early,medium,and late stages of bud development(F1,F5,F9).Transcription factor families such as AP2-ERF,MADS-box,MYB,bHLH,and NAC showed significant levels of enrichment.In comparison with genes expressed in vegetative tissues at different stages,certain genes were specifically up-regulated during flower development;among these,the number of genes specifically up-regulated during the stamen(Sta10)and bud tetrad development(F4)stages was the highest.Through extensive studies of the ABCDE model of flower development in Arabidopsis,we identified 17 ABCDE model candidate genes in pepper,most of which were up-regulated at specific stages of flower bud development.The expression data provided in this study is the most comprehensive dataset available for pepper to date and will serve as a resource for identifying the functions of many specific genes involved in flower development in pepper and other Solanaceae plants.

The BnTFL1–BnGF14nu–BnFD module regulates flower development and plant architecture in Brassica napus

Flower development and plant architecture determine the efficiency of mechanized harvest and seed yield in Brassica napus.Although TERMINAL FLOWER 1(AtTFL1)is a regulator of flower development in Arabidopsis thaliana,the function and regulatory mechanism of TFL1 orthologs in B.napus remains unclear.Six BnTFL1 paralogs in the genome of the B.napus inbred line‘K407’showed steadily increasing expression during vernalization.CRISPR/Cas-induced mutagenesis of up to four BnTFL1 paralogs resulted in early flowering and alteration of plant architecture,whereas seed yield was not altered in BnTFL1 single,double,or triple mutants.Six BnTFL1 paralogs,but not BnaA02.TFL1,showed an additive and conserved effect on regulating flowering time,total and terminal flower number,and plant architecture.BnaA10.TFL1 regulates flower development by interacting with BnaA08.FD through the protein BnaA05.GF14nu,resulting in the transcriptional repression of floral integrator and floral meristem identity genes.These findings about the regulatory network controlling flower development and plant architecture present a promising route to modifying these traits in B.napus.

Flower Development and Photoperiodic Control of Flowering in Rice

Floral transition,which is referred to as a plant＇s transition from vegetative stage to reproductive stage,is considered to be a critical developmental switch in higher plants,for a timely flowering is a major factor of reproductive success.Endogenous and environmental cues,such as photoperiod,light quality,plant hormones concentrations and temperature,provide information to the plants whether the environment is favorable for flowering.These cues promote,or prevent,flowering through a complex genetic network,mediated by a careful orchestration of temporal and spatial gene expression.One of such cues is photoperiod.Rice（Oryza sativa L.） serves as a powerful model species for the understanding of flowering in higher plants,including flower development and photoperiodic control of flowering.In this review,we overviewed and discussed the flower development and its model.We also overviewed the photoperiodic pathways in rice flowering control,and summarized the pathways at molecular level.

Comparative microsporogenesis and flower development in Eucalyptus urophylla×E.grandis

Microsporogenesis and flower development in Eucalyptus urophylla × E. grandis were examined using chromosome tableting to provide a method to predict the meiotic stages in this species. Although microsporogenesis was normal, cytokinesis during meiosis of pollen mother cells occurred simultaneously, with strong asynchronism observed in the two different lengths of stamens in a flower bud. In a single flower, the developmental period of microsporogenesis in anthers on the longer stamens was always ahead of those on the shorter stamens. Flower development was also asynchronous at different locations on a branch. Flower buds on the upper side of the branch were larger in diameter than those on the lower side. In addition, a correlation was observed between microsporogenesis development and flower bud diameter growth. The pachy- tene stage was first observed when the diameter of the flower buds increased to 3.0 mm, and the majority of the meiotic stages were observed when bud diameters ranged from 3.5 to 5.0 mm. This study showed that the developmental stages of microsporogenesis in Eucalyptus urophylla × E. grandis could be distinguished readily, which may be applicable to future breeding studies.

Characterization and Genetic Analysis of a Novel Mutant mst of Rice Defective in Flower Development

A spontaneous mutant with multiple stigmas （msf） was found in an indica rice line 466. The mst mutant exhibits normal at the vegetative development stage and produces normal inflorescence structures. The difference between the mutant and the wild type was observed when the stamen primordium began to develop. In the mst florets, palea and lemma opened, Iodicules were homeotically transformed into palea/lemma-like structures, and stamens were homeotically transformed into carpel-like structures. It looked like multiple stigmas being full of the whole floret. The phenotypic changes of rest were very similar to that of B-like mutant spwl. Compared with other mutants with pistillate morphologies, the severe mstflorets showed that the inner three floral organs were completely changed into palea/lemma-like structures. Moreover, the mutant was female sterile. Occasionally, with the changing environment, one or two stamens were fertile. Genetic analysis indicated that the mutant traits were controlled by a single recessive gene.

Effects of H_2O_2 and NO on Flower Development and AP1 Gene Expression of Off-season Longan

[Objective] This study aimed to investigate the effects of H2O2 and NO on flower development and 4P1 gene expression of off-season longan. [Meth-od ]Nine-year-old off-season Chuliang longan was sprayed with enhancers and blockers of H2O2 and NO to analyze dynamic changes of flower development and API expression. [ Result] The expression level of API gene in off-season longan was improved during flower development. SNP and MV treatments up-regulated the expression level of API gene in leaves and terminal buds to varying degrees during lateral primordium formation. Especially, SNP treatment exhibited the most remark-able effect. DMTU treatment significantly inhibited the expression of AP1 gene in leaves and terminal buds during lateral primordium formation. L-NNA treatment slightly inhibited the expression of API gene in leaves and exerted no significant effect on expression of AP1 gene in terminal buds. [ Conclusion] It can be specu-lated that the enhancement of NO and H2O2 signals is conducive to flower development of off-season longan, while blocking H2O2 signals may inhibit flower develop-ment of off-season longan.

Conserved Functions of Arabidopsis and Rice CC-Type Glutaredoxins in Flower Development and Pathogen Response

Glutaredoxins （GRXs） are ubiquitous oxidoreductases that play a crucial role in response to oxidative stress by reducing disulfides in various organisms. In planta, three different GRX classes have been identified according to their active site motifs. CPYC and CGFS classes are found in all organisms, whereas the CC-type class is specific for higher land plants. Recently, two Arabidopsis CC-type GRXs, ROXY1 and ROXY2, were shown to exert crucial functions in petal and anther initiation and differentiation. To analyze the function of CC-type GRXs in the distantly related monocots, we isolated and characterized OsROXY1 and OsROXY2-two rice homologs of ROXY1. Both genes are expressed in vegetative and reproductive stages. Although rice flower morphology is distinct from eudicots, OsROXY1/2 floral expression patterns are similar to their Arabidopsis counterparts ROXY1/2. Complementation experiments demonstrate that OsROXY1 and OsROXY2 can fully rescue the roxyl floral mutant phenotype. Overexpression of OsROXY1, OsROXY2, and ROXY1 in Arabidopsis causes similar vegetative and reproductive plant developmental defects. ROXY1 and its rice homologs thus exert a conserved function during eudicot and monocot flower development. Strikingly, overexpression of these CC-type GRXs also leads to an increased accumulation of hydrogen peroxide levels and hyper-susceptibility to infection from the necrotrophic pathogen Botrytis cinerea, revealing the importance of balanced redox processes in flower organ develop- ment and pathogen defence.

Functional Diversity of CYCLOIDEA-like TCP Genes in the Control of Zygomorphic Flower Development in Lotus japonicus

CYCLOIDEA （CYC）-like TCP genes play key roles in dorsoventral differentiation of zygomorphic flowers in Papilionoideae legumes. In this study, we analyzed the kew mutants whose flowers lost lateral identity, and investigated the diverse functions of three LjCYC genes during zygomorphic flower development in the model legume Lotus japonicus. We showed that kew1 and kew3 are allelic mutants of LjCYC3, a CYC-like TCP gene. Through transgenic experiments, it was shown that LjCYC1 possesses dorsal activity similar to LjCYC2, and that LjCYC3 alone is sufficient to confer lateral activity, and an epistatic effect between dorsal and lateral activities was identified. Sequence analysis revealed a striking alteration at the 3 end of the LjCYC3 open reading frame （ORF） in comparison with those of LjCYC1 and LjCYC2 ORFs. Furthermore, it was found that LjCYC proteins could interact with each other and possess different activities by means of a transcriptional activity assay. Our data demonstrate that the sequence variation and the subsequent alteration of protein property play important roles in the functional diversity of different LjCYC genes in controlling zygomorphic flower development in Lotus japonicus.

Transcriptional and Post-transcriptional Modulation of SQU and KEW Activities in the Control of Dorsal-Ventral Asymmetric Flower Development in Lotus japonicus

In Papilionoideae legume, Lotusjaponicus, the development of dorsal-ventral （DV） asymmetric flowers is mainly controlled by two TB1/CYCLOIDEA/PCF （TCP） genes, SQUARED STANDARD （SQU） and KEELED WINGS IN LOTUS （KEW）, which determine dorsal and lateral identities, respectively. However, the molecular basis of how these two highly homologous genes orchestrate their diverse functions remains unclear. Here, we analyzed their expression levels, and investigated the transcriptional activities of SQUand KEW. We demonstrated that SQU possesses both activation and repression activities, while KEW acts only as an activator. They form homo- and heterodimers, and then collaboraUvely regulate their expression at the transcription level. Furthermore, we identified two types of post-transcriptional modifications, phosphor- ylation and ATP/GTP binding, both of which could affect their transcriptional activities. Mutations in ATP/ GTP binding motifs of SQU and KEW lead to failure of phosphorylation, and transgenic plants bearing the mutant proteins display defective DV asymmetric flower development, indicating that the two conjugate modifications are essential for their diverse functions. Altogether, SQU and KEW activities are precisely modulated at both transcription and post-transcription levels, which might link DV asymmetric flower development to different physiological status and/or signaling pathways.

Global Lysine Acetylome Analysis of Flower Bud Development in Catalpa bungei

Lysine acetylation,a reversible and dynamic post-translational modification,plays pivotal roles in regulating many biological processes in plants.However,the information of lysine acetylation during flower development of woody angiosperm remains unclear.Herein,we identified a total of 667 lysine acetylation sites in 467 proteins in flower buds of Catalpa Bungei.The acetylated proteins were mainly involved in the pathways of carbon metabolism,glycometabolism and oxidative phosphorylation.Using functional enrichment analysis,61 and 13 acetylated proteins were involved in the glycometabolism and oxidative phosphorylation pathways,respectively.This suggests that lysine acetylated proteins play critical roles in the energy metabolism pathways.Accordingly,the protein–protein interactions were also highly enriched in the carbon metabolic pathway.Integrative analysis of lysine acetylome and transcriptome showed that transcript level changes of seven key lysine-acetylated proteins/genes involved in energy metabolism were significant different during floral transition.Importantly,compared with the normal flowering variety,the expression levels of phosphoribulokinase,phosphoenolpyruvate carboxykinase,ATP synthase and pyruvate dehydrogenase complex genes were significantly up-regulated at the stages of vegetative and transition buds during early flowering of C.bungei.These data represent the first lysine acetylome in the C.bungei flowers,and can serve as an essential basis for exploring the function of lysine acetylated proteins in the flower bud development of plants.

VvAGAMOUS Affect Development of Four Different Grape Species Ovary

Grape pistil has an important influence on fruit size and quality.However,there were few studies on grape ovary,and the development process of the ovary is still unclear.Therefore,in this paper,four different grape varieties with different lengths of small inflorescences,namely‘Musct Hambourg’grape(Vitis vinifera),‘Concord’grape(Vitis labrusca),‘ShanPuTao’grape(Vitis amurensis)and‘GongNiang2Hao’grape(Vitis amurensis×Vitis vinifera)were used as test materials.Four varieties ovary were significant differences by means of stereomicroscope,paraffin section.The expression of ovary determining gene VvAGAMOUS(VvAG)and its development related genes VvCRABS CLAW(VvCRC)and VvAGAMOUS-LIKE 11(VvAGL11)with similar functions during the development of different grape varieties were preliminarily explored using fluorescence quantitative test.The relationship between VvAG and VvCRC,VvAG and VvAGL11 were analyzed using Y1H assay.Our results showed that there were obvious abdominal sutures on the surface of expect for‘Musct Hambourg’grape,and existing poly carpels.The ovary development of‘ShanPuTao’and‘GongNiang2Hao’grape was completed when the inflorescence length was less than 1 cm,while the‘Concord’and‘Musct Hambourg’grape were fully developed when the length of inflorescence was 3–4 and 4–5 cm,respectively.VvAG and VvCRC began to express in large quantities after the formation of stamen primordia,while VvAGL11 during the forming of ovule primordia.Therefore,VvAG and VvCRC mainly regulated the development of stamens and carpels and also promote the development of ovules,while VvAGL11 major regulated the development of ovules.The promoters of VvCRC and VvAGL11 were bound by VvAG.This study provides an important theoretical basis for further research on the molecular mechanism of grape ovary development.

B Class Floral Homeotic Genes are Involved in the Petal Identity and Flower Meristem Determinations in Chrysanthemum morifolium

Chrysanthemum morifolium,an ornamental crop with diverse forms of inflorescence,is a good model for studying flower development in Asteraceae.However,the genetic background is complex and the mechanisms of regulating flower development are still unclear.Here,we identified two natural mutant lines of chrysanthemum and named them M1 and M2 according to the severity of the phenotype.Both lines showed defects in petal identity,and the petals of the M1 line had a mild phenotype:partially loss of petal identity and conversion of petals into green,leaf-like organs.The M2 line had severe phenotypes:in addition to severe petal defects,secondary inflorescences were produced in the capitulum to replace the normal ray and disc florets,which indicated a transformation of a flower meristem into an inflorescence meristem.Transcriptome sequencing of WT and M2 inflorescences was performed and found altered expression of floral organ development A,B and E class genes,where B and E class genes were significantly down-regulated.qRT-PCR analysis in both M1 and M2 lines revealed that the expression of three chrysanthemum class B genes CmAP3.1,CmAP3.2 and CmPI,was negatively correlated with phenotypic severity.This suggests that class B genes in chrysanthemum not only have conserved functions in determining petal identity but also were involved in the determinacy of the flower meristem.This study provides insights into the functions of class B genes in flower development,and is informative for dissecting the molecular mechanisms of flower development in chrysanthemum.

Transcriptomic profiling of watermelon(Citrullus lanatus) provides insights into male flowers development

Watermelon(Citrullus lanatus(Thunb.) Matsum. & Nakai) is an important cucurbit crop grown worldwide. Watermelon fruit quality, fertility, and seed-setting rate are closely related to male flower development. In this study, the different developmental stages of flower buds of the watermelon cultivar ’Xinteda Zhengkang 9’ were distinguished by cytological observation, and transcriptome sequencing analysis was performed subsequently. Acetocarmine staining of anthers was performed and the longitudinal and transverse diameters of the unopened male flower buds were measured. Cytological observations of anthers at different developmental stages showed that the anther grew from the tetrad to the mature stage, and the longitudinal and transverse diameters of the flower buds increased. The length of the male flower buds also changed significantly during development. Transcriptome sequencing analysis at four periods, the tetrad(A group), mononuclear(B group), dikaryophase(C group), and mature stages(D group). A total of 16 288 differentially expressed genes(DEGs) were detected in the four stages, with the prolongation of developmental stages, the number of DEGs increased gradually in the comparison groups, there was 2 014, 3 259, 4 628, 1 490, 3 495 and 1 132 DEGs revealed in six comparison groups(A-vs.-B, A-vs.-C, A-vs.-D, B-vs.-C, B-vs.-D, and C-vs.-D), respectively. Gene Ontology(GO) and KEGG enrichment analysis showed that the DEGs were mainly enriched in cellular component and starch and sucrose metabolism, phenylpropanoid biosynthesis and pentose sugar, etc. Finally, we completely screened 59 DEGs in the six comparison groups, interestingly, we found one pollen-specific protein(Cla001608) that was significantly down-regulated(the value of log2 Fold Change up to 17.32), which indicated that it may play an important role in the development of male flowers. This work provides insight into the molecular basis of the developmental stages of male flowers in watermelon and may aid in dominant cross breeding.

cDNA-Amplified fragment length polymorphism analysis reveals differential gene expression induced by exogenous MeJA and GA_3 in oilseed rape (Brassica napus L.) flowers

The transition of a plant from vegetative to reproductive stage is controlled by a large group of genes, which respond to environmental and endogenous stimuli. Application of methyl jasmonate （MeJA） and gibberellins （GA3） to oilseed plants （Brassica napus L.） interrupts the delicate endogenous balance and results in various floral organ abnormalities. Exogenous MeJA or GA3 influences the transcriptome at the initial fiowenng stage in Arabidopsis, but the corresponding changes of transcriptome in floral tissues of oilseed rape remain unknown. In this study, cDNA-amplified fragment length polymorphism （cDNA-AFLP） was analyzed to identify genes whose expression was modulated by application of MeJA and GA3 to flower buds. A total of 2 787 cDNA fragments were counted using 64 primer pair combinations, and bands larger than 50 bp were compared among four treatments, namely, water control, MeJA （50 μmol L-1）, MeJA （100 μmol L-1）, and GA3 （50 μmol L-1）. Overall, 168 transcript-derived fragments （TDFs） were differentially expressed among the treatments. The expression pattern of some TDFs was confirmed by semi-quantitative RT-PCR analysis, and a group of 106 differentially displayed TDFs was cloned and sequenced. Homologs of Arabidopsis genes were identified and classified into 12 functional categories. A total of 34, 39, and 24 TDFs were responsive to GA3, MeJA, and both GA3 and MeJA, respectively. This finding indicated that cross-talk between these two hormones may be involved in regulating flower development. This study provides potential target genes for manipulation in terms of flowering time and floral organ initiation, important agronomic traits of oilseed rape.

Synergistic roles of LAX1 and FZP in the development of rice sterile lemma

Rice florets are subtended by two sterile lemmas,whose origin and biological functions have not been studied extensively.Here we demonstrate that two putative transcription factors,LAX PANICLE1(LAX1)and FRIZZY PANICLE(FZP),synergistically control the development of sterile lemmas.Both LAX1 and FZP are previously known for their roles in panicle and floret development.Disruption of either LAX1 or FZP greatly reduces the number of floret development.We generated new lax1 mutants(lax1-c)using CRISPR/Cas9 gene editing technology.In addition to the expected lax panicle phenotypes,we noticed that a significant number of spikelets of lax1-c developed elongated sterile lemmas.Moreover,our characterization of lax1-RNAi plants also revealed sterile lemma phenotypes similar to lax1-c mutants.We isolated a weak allele of fzp(fzp-14)in a genetic screen for lax1–1 enhancers.The fzp-14 lax1–1 double mutants completely eliminated flower development.Interestingly,the isolated fzp-14 produced spikelets with elongated sterile lemmas.Furthermore,fzp-14 was haploid-insufficient in the lax1–1 background whereas fzp-14 heterozygous plants were indistinguishable from wild type plants.The lax1–1 fzp-14+/−also developed elongated sterile lemma as observed in lax1-c,lax1-RNAi,and fzp-14,suggesting that LAX1 and FZP synergistically control sterile lemma development.

气候变化对‘红地球’葡萄发育期及花序开放的影响

为适应气候变化,促进北疆地区葡萄产业持续稳定的发展,采取平行观测和试验方法,通过试验观测研究气象要素变化对葡萄生长发育期以及花序开放的影响。结果表明,北疆葡萄生长期在4月中下旬—10月中旬,休眠期在10月下旬—4月上中旬。‘红地球’葡萄萌芽至可采成熟≥10℃活动积温、开花期气温与葡萄产量显著相关。葡萄开花期为生长关键期,一般需要持续1~2周,盛花期2~3 d。花序开放日动态表现为明显的双峰曲线,10:00—12:00时开花最多,14:00—16:00时空气干燥、气温超过30℃花序开放减少步入低谷。葡萄花序开放温度在16~30℃之间,最适宜温度为22~26℃。葡萄开花最适合空气相对湿度在50%~80%之间。葡萄盛花期花序开放日变化与净光合速率日变化吻合,相关系数达到极显著水平。温度、湿度、光照是影响葡萄生长及花序开放的3个重要环境要素。试验结果可为研究葡萄生物学特征、预防气象灾害和安全生产提供参考。

顶空气质联用法鉴别不同发育期蚕豆花挥发性成分

通过研究不同发育期蚕豆花的挥发性成分,解析蚕豆花挥发性成分的生物功能,为蚕豆花挥发性成分的开发利用提供科学依据。采用顶空气质联用法对不同发育期蚕豆花的挥发性成分进行检测分析。结果表明:从蚕豆花中共分离鉴定出35种挥发性成分,包括醇类、酯类、醛类、酮类、萜烯类、烷烃类、芳香族类、生物碱类等。从花蕾期、初开期、盛开期、凋谢期蚕豆花中分别鉴定出12、14、18、20种挥发性成分,相对总含量分别为80.90%、83.46%、81.53%、84.56%。蚕豆花花蕾期主要挥发性成分有苯乙醇、正己醛、溴化香叶酯、蘑菇醇,初开期主要挥发性成分有正己醛、溴化香叶酯、蘑菇醇,盛开期主要挥发性成分有β-蒎烯、正己醛,凋谢期主要挥发性成分有β-蒎烯、正己醛、苯甲醛、苯乙醇。随着蚕豆花的生长发育,挥发性成分的数量逐渐增加。醇类、酯类、醛类、萜烯类成分是蚕豆花的主要挥发性物质,对蚕豆花气味具有重要贡献。蚕豆花挥发性成分在吸引虫媒、抵御病原菌和害虫侵害中发挥重要作用,凋谢期蚕豆花挥发性成分丰富,可提取用于开发昆虫引诱剂、驱避剂或植物源天然保鲜剂。

菜心小孢子发育时期与花器官形态的相关性

研究菜心小孢子不同发育时期的细胞学特征及其与花器官外部形态的相关性,为直接从花器官外部形态特征来判断小孢子发育时期提供依据。结果表明,菜心小孢子发育分为四分体时期、单核期和双核期,各时期特征明显。菜心小孢子发育时期与花蕾和花药外部形态特征密切相关,供试菜心材料中处在单核靠边期的花蕾纵径为3.05～3.39 mm,花萼长为3.25～3.46 mm,花瓣长为2.10～2.33 mm,瓣萼比为0.63～0.71,花药长为2.57～2.89 mm、瓣药比为0.77～0.85,适合作为不同材料花蕾最佳取样时期的鉴定指标。处在单核靠边期的花器官外观特征表现为花蕾饱满,萼片绿色并包被着花冠,花瓣和花药均为浅黄色,花药略长于花瓣。可见,依据花器官形态特征可判断菜心小孢子的发育时期及所对应的选蕾标准。