油菜抗裂果性研究简述

本简述了油菜易裂果性的危害、抗裂果性研究的意义及国内外研究现状和进展；也介绍了我国现有的主要抗裂果性油菜资源，并提出国内应开展油菜抗裂果性遗传机理研究和转基因研究的建议。     

枣果吸水动力学特征和果皮显微结构对裂果的影响

裂果是对枣产量和品质影响最大、最难防治的生理性病害,本研究旨在揭示抗裂果枣品种的抗性机制,为有效防治枣裂果和选育抗裂果枣品种提供依据。选择不同抗裂等级的枣品种为试材,通过室内浸水试验研究枣果水势、持水率、吸水率、吸水速率等吸水动力学指标与裂果率和裂果指数等抗裂等级指标之间的相关性,同时利用组织切片技术观测果皮显微结构与抗裂等级的关系。结果表明,枣果水势高低不能反映枣果固有的抗裂等级;枣果的持水率与裂果率、裂果指数之间均没有显著相关性;脆熟期枣果的吸水率与裂果率和裂果指数呈极显著正相关;吸水率阈值时的吸水速率随枣果抗裂等级的升高逐渐降低,极抗裂品种长红枣和极易裂品种骏枣吸水率阈值时的吸水速率分别为0.20%/h和0.52%/h;极抗裂品种长红枣的果皮蜡被厚度极显著高于其他品种,而且果皮细胞排列规则紧密;枣果抗裂性与果皮厚度相关性不显著;果实中上部(近果柄端)为开裂的敏感部位。     

新疆厚皮甜瓜裂果抗性及其生理特征分析

以种植于新疆农业科学院哈密瓜研究中心吐鲁番亚尔乡基地的20份新疆厚皮甜瓜品种为研究对象,在果实成熟期测定各品种裂果指数,裂果率、果皮及果肉矿物质元素含量、纤维素含量、半纤维素含量、过氧化物酶(POD)活性、多酚氧化酶(PPO)活性等,以筛选评价厚皮甜瓜抗裂果品种,明确影响厚皮甜瓜裂果的主要内在因子,为甜瓜的栽培生产与新品种选育提供理论支持。结果表明:(1)依据裂果指数将20份新疆厚皮甜瓜品种裂果抗性划分为5个等级,其中极抗裂等级3份,抗裂等级5份,较易裂等级5份,易裂等级4份,极易裂等级3份;(2)极易裂型中果皮含水量显著高于极抗裂和较易裂型,而其心糖含量显著低于极抗裂和较易裂型;果皮中Ca、Na、Mg、Fe元素含量显著高于果肉含量;极易裂型中PPO活性显著低于较易裂型,其POD活性显著高于极抗裂和较易裂型,其纤维素含量、半纤维素含量显著低于极抗裂型。(3)裂果抗性与果实心糖含量、纤维素含量、半纤维素含量存在显著正相关,与果皮含水量、果肉含水量、POD活性、K元素含量存在显著负相关。(4)甜瓜裂果性的主要影响因子有果皮含水量、果肉含水量、心糖含量、边糖含量、纤维素含量,果皮中的K、Ca、Mg、Na含量以及果肉的Na、Cu含量。研究发现,甜瓜‘黄梦脆’、‘K1028’、‘西州密17’为极抗裂品种,裂果率、裂果指数、心糖含量、果皮含水量、果肉含水量、纤维素含量、K含量可作为甜瓜裂果研究中的重要指标。     

新疆6个大果红枣裂果性差异及其内在原因分析

该研究以新疆栽培的6个大果型红枣品种(‘骏枣’、‘赞新大枣’、‘金谷大枣’、‘蛤蟆枣’、‘晋赞大枣’、‘新郑大马牙’)全红期果实为对象,通过考察裂果性差异,观察果皮组织结构,测定细胞壁成分及代谢相关酶活性,分析扩展蛋白基因表达的变化,探讨造成枣品种裂果差异的内在规律,为栽培引种及抗裂品种选育提供理论基础。结果表明:(1)‘骏枣’、‘赞新大枣’、‘金谷大枣’属于易裂果品种,而‘蛤蟆枣’、‘晋赞大枣’、‘新郑大马牙’的抗裂果能力较强。(2)6个品种之间的果实角质层厚度差异显著,并以‘晋赞大枣’、‘蛤蟆枣’和‘新郑大马牙’较大;表皮层厚度在品种之间无显著差异;品种间的果肉空腔与果肉面积比例差异显著,由低到高依次为‘蛤蟆枣’‘新郑大马牙’‘晋赞大枣’‘骏枣’‘金谷大枣’‘赞新大枣’。(3)6个品种间果皮的纤维素含量、纤维素酶活性以及原果胶含量、可溶性果胶含量、果胶酶活性等指标均存在显著差异,且原果胶含量与裂果率具有相关性,抗裂品种‘晋赞大枣’和‘蛤蟆枣’的原果胶含量明显低于其他品种;其他指标与它们各自的裂果率未发现相关性。(4)扩展蛋白基因ZjEXP11和ZjEXP12在6个品种果皮中的表达水平差异显著,且与裂果率具有相关关系,并以抗裂果能力较强品种的表达量显著较低。研究发现,新疆大果型红枣的裂果性在品种间存在显著差异,抗裂果品种比易裂果品种具有更厚的角质层和表皮层,以及更小的果肉空腔面积、更低的原果胶含量和更低的扩展蛋白基因ZjEXP11、ZjEXP12表达水平。     

CaCl2浸果对新疆枣裂果率及钙钾镁含量的影响

以新疆产不同抗裂性枣品种‘骏枣’、‘哈密大枣’、‘灰枣’、‘金铃圆枣’果实为试验材料,用不同浓度CaCl2(0、2.5、25g/L)分别浸泡12、36、60h,研究CaCl2对枣裂果率及果肉、果皮中Ca、K、Mg含量的影响。结果显示:(1)2.5、25g/L CaCl2均能有效降低枣裂果率,且25g/L CaCl2对各品种枣的防裂效果均优于2.5g/L CaCl2。(2)极抗裂品种枣的果皮、果肉中Ca显著高于极易裂品种,且各品种Ca含量均随CaCl2浓度增加而增加。(3)极抗裂品种枣的果皮、果肉中K含量高于极易裂品种,其Mg含量则表现出相反趋势,但不同浓度CaCl2处理的枣果肉、果皮中Mg、K升降幅度变化不同。(4)枣果肉、果皮中Ca、K含量与裂果率呈负相关关系,Mg含量与裂果率呈正相关关系。研究认为,CaCl2浸果能有效增加枣果肉、果皮中钙含量,影响各品种枣果实的钾镁含量,显著降低枣裂果率,并以25g/L CaCl2效果最好。     

裂果薯的化学成分研究——皂甙甲和乙

从裂果薯(Tacca plantaginea Drenth)中分离到甲、乙、丙三个甾体化合物。化物合甲和乙,经光谱解析和化学分析鉴定为两个新甾体皂甙。其中裂果薯皂甙甲(Ⅱ)为一个糖连接方式上不常见的皂甙(约茂皂甙元-3-O-β-D-吡喃葡萄糖(1→2)[α-L-吡喃鼠李糖(1→3)][α-L-吡喃鼠李糖(1→4)]-β-D-吡喃葡萄糖甙);裂果薯皂甙乙(Ⅲ)(约茂皂甙元-3-O-α-L-吡喃鼠李糖(1—2)[α-L-吡喃鼠李糖(1→3)]-β-D-吡喃葡萄糖甙)。丙为豆甾醇甙。     

白沙枇杷果实发育、果实水势及与裂果关系研究

对生长在山坡地6年生白沙枇杷(Eriobotrya japonica Lindl.)的裂果与果实发育、可溶性糖含量、土壤相对含水量及果实水势关系进行了研究,并探讨了覆盖地膜、断根和果实套袋技术对预防裂果的效果。结果表明,随着白沙枇杷果实的发育,果形指数变小;临近成熟期,果实的可溶性糖含量最高,土壤相对含水量增加,同时果实水势也升高。模拟大雨后,果实水势与裂果率呈正相关,相关系数R=0.941。这说明白沙枇杷临近成熟时,果实内积累了大量的可溶性糖等高渗透物质,从高含水量的土壤中大量吸收水分,使果实水势升高,导致裂果。以覆盖地膜、断根和果实套袋组合的技术预防裂果的效果最好,其中覆盖地膜和断根对预防裂果的贡献较大。     

温州蜜柑裂果因子调查初报

通过对1990年温州蜜柑裂果的调查,初步探明了不同品系,不同的基砧、中间砧及砧木高度,树体在园中所处的位置,树体的不同部位、树势,结果枝上的裂果顺序,灌溉条件,气象要素的变化,果实某些指标的差异等因子与裂果的关系。据此,提出防止裂果措施。     

香梨的果表突起和落果裂果与果实中内源激素之间的关系（简报）

6月初香梨落果中GA3、IAA含量高于发育正常的果实,ABA含量几无变化。7月底、8月初果实迅速膨大期间,无论裂果与否的果实中均未检出IAA,但裂果中GA3和ABA含量均高于而GA3／ABA则低于发育正常果0实。萼端突起部位的内源激素含量高于梨身。     

枣果吸水动力学和果皮特征对裂果的影响

裂果是对枣产量和品质影响最大、最难防治的生理性病害,本研究旨在揭示抗裂果枣品种的抗性机制,为有效防治枣裂果和选育抗裂果枣品种提供依据。选择不同抗裂等级的枣品种为试材,通过室内浸水试验研究枣果水势、持水率、吸水率、吸水速率等吸水动力学指标与裂果率和裂果指数等抗裂等级指标之间的相关性,同时利用组织切片技术观测果皮显微结构与抗裂等级的关系。结果表明,枣果水势高低不能反映枣果固有的抗裂等级;枣果的持水率与裂果率、裂果指数之间均没有显著相关性;脆熟期枣果的吸水率与裂果率和裂果指数呈极显著正相关;吸水率阈值时的吸水速率随枣果抗裂等级的升高逐渐降低,极抗裂品种长红枣和极易裂品种骏枣吸水率阈值时的吸水速率分别为0.20%/h和0.52%/h;极抗裂品种长红枣的果皮蜡被厚度极显著高于其他品种,而且果皮细胞排列规则紧密;枣果抗裂性与果皮厚度相关性不显著;果实中上部(近果柄端)为开裂的敏感部位。     

Pod shattering in grain legumes: emerging genetic and environment-related patterns

A reduction in pod shattering is one of the main components of grain legume domestication. Despite this, many domesticated legumes suffer serious yield losses due to shattering, particularly under arid conditions. Mutations related to pod shattering modify the twisting force of pod walls or the structural strength of the dehiscence zone in pod sutures. At a molecular level, a growing body of evidence indicates that these changes are controlled by a relatively small number of key genes that have been selected in parallel across grain legume species, supporting partial molecular convergence. Legume homologs of Arabidopsis thaliana silique shattering genes play only minor roles in legume pod shattering. Most domesticated grain legume species contain multiple shattering-resistance genes, with mutants of each gene typically showing only partial shattering resistance. Hence, crosses between varieties with different genes lead to transgressive segregation of shattering alleles, producing plants with either enhanced shattering resistance or atavistic susceptibility to the trait. The frequency of these resistance pod-shattering alleles is often positively correlated with environmental aridity. The continued development of pod-shattering-related functional information will be vital for breeding crops that are suited to the increasingly arid conditions expected in the coming decades.

Recent genetic, genomic, and phenotypic studies of pod shattering in grain legumes lay the foundation for breeding crops suited for increasingly arid conditions.     

Formation Mechanism and Occurrence Law of Pod Shattering in Soybean: A Review

Seed shattering refers to the phenomenon in which the pods split along the abdominal and back sutures before the crop is received, so that the seeds are spread. Seed shattering is vital to the reproduction of their offspring in wild plants, but it is also the main cause of crop yield loss reason. Pod-explosion resistance is a complex process of physical and physiological and biochemical reactions. Soybean seed shattering phenomenon is widespread, which severely restricts the development of soybean industry. Seed shattering (pod cracking or fruit dropping) is essential for the reproduction of its offspring in wild plants, but it is also the main cause of crop yield loss. This article analyzes the morphology and structure of pods related to seed shattering from the morphology of pods. On the basis of the regularity of the occurrence of seed shattering and the summary of phenotypic index identification methods, physiologically introduced the regulation mechanism of key enzymes and endogenous hormones on seed shattering. The localization, labeling and cloning of seed shattering genes are introduced in molecular biology. The study focused on reviewing the latest advances in the research on soybean seed shattering characteristics, and discussed with the research results of related crops. Finally, the research and application of soybean seed shattering resistance were prospected for several aspects.     

Discovery of pod shatter-resistant associated SNPs by deep sequencing of a representative library followed by bulk segregant analysis in rapeseed

Background

Single nucleotide polymorphisms (SNPs) are an important class of genetic marker for target gene mapping. As of yet, there is no rapid and effective method to identify SNPs linked with agronomic traits in rapeseed and other crop species.

Methodology/Principal Findings

We demonstrate a novel method for identifying SNP markers in rapeseed by deep sequencing a representative library and performing bulk segregant analysis. With this method, SNPs associated with rapeseed pod shatter-resistance were discovered. Firstly, a reduced representation of the rapeseed genome was used. Genomic fragments ranging from 450–550 bp were prepared from the susceptible bulk (ten F2 plants with the silique shattering resistance index, SSRI <0.10) and the resistance bulk (ten F2 plants with SSRI >0.90), and also Solexa sequencing-produced 90 bp reads. Approximately 50 million of these sequence reads were assembled into contigs to a depth of 20-fold coverage. Secondly, 60,396 ‘simple SNPs’ were identified, and the statistical significance was evaluated using Fisher''s exact test. There were 70 associated SNPs whose –log₁₀ p value over 16 were selected to be further analyzed. The distribution of these SNPs appeared a tight cluster, which consisted of 14 associated SNPs within a 396 kb region on chromosome A09. Our evidence indicates that this region contains a major quantitative trait locus (QTL). Finally, two associated SNPs from this region were mapped on a major QTL region.

Conclusions/Significance

70 associated SNPs were discovered and a major QTL for rapeseed pod shatter-resistance was found on chromosome A09 using our novel method. The associated SNP markers were used for mapping of the QTL, and may be useful for improving pod shatter-resistance in rapeseed through marker-assisted selection and map-based cloning. This approach will accelerate the discovery of major QTLs and the cloning of functional genes for important agronomic traits in rapeseed and other crop species.     

大豆炸荚发生规律及分子遗传基础

炸荚是野生大豆繁衍后代的一种原始自然属性,同时也是栽培大豆减产的主要原因之一,因此对其发生规律和分子遗传基础的研究具有重要的理论意义和潜在的育种应用价值。文章在剖析抗炸荚大豆荚部细胞学微观组织结构特征的基础上,总结了大豆炸荚的发生规律和大豆炸荚表型性状的鉴定指标与方法,介绍了抗炸荚种质鉴定与抗炸荚品种选育概况,同时详细阐述了大豆抗炸荚性状的分子遗传基础研究进展,最后对大豆抗炸荚性的研究与应用进行了展望。     

Identification of SNPs tightly linked to the QTL for pod shattering in soybean

The pod shattering or dehiscence is essential for the propagation of pod-bearing plant species in the wild, but it causes significant yield losses during harvest of domesticated crop plants. Identifying novel molecular makers, which are linked to seed-shattering genes, is needed to employ the molecular marker-assisted selection for efficiently developing shattering-resistant soybean varieties. In this study, a genetic linkage map was constructed using 115 recombinant inbred lines (RILs) developed from crosses between the pod shattering susceptible variety, Keunol, and resistant variety, Sinpaldal. A 180 K Axiom® SoyaSNPs data and pod shattering data from two environments in 2001 and 2015 were used to identify quantitative trait loci (QTL) for pod shattering. A major QTL was identified between two flanking single nucleotide polymorphism (SNP) markers, AX-90320801 and AX-90306327 on chromosome 16 with 1.3 cM interval, 857 kb of physical range. In sequence, genotype distribution analysis was conducted using extreme phenotype RILs. This could narrow down the QTL down to 153 kb on the physical map and was designated as qPDH1-KS with 6 annotated gene models. All exons within qPDH1-KS were sequenced and the 6 polymorphic SNPs affecting the amino acid sequence were identified. To develop universally available molecular markers, 38 Korean soybean cultivars were investigated by the association study using the 6 identified SNPs. Only two SNPs were strongly associated with the pod shattering. These two identified SNPs will help to identify the pod shattering responsible gene and to develop pod shattering-resistant soybean plants using marker-assisted selection.     

Genome-Wide Delineation of Natural Variation for Pod Shatter Resistance in Brassica napus

Resistance to pod shattering (shatter resistance) is a target trait for global rapeseed (canola, Brassica napus L.), improvement programs to minimise grain loss in the mature standing crop, and during windrowing and mechanical harvest. We describe the genetic basis of natural variation for shatter resistance in B. napus and show that several quantitative trait loci (QTL) control this trait. To identify loci underlying shatter resistance, we used a novel genotyping-by-sequencing approach DArT-Seq. QTL analysis detected a total of 12 significant QTL on chromosomes A03, A07, A09, C03, C04, C06, and C08; which jointly account for approximately 57% of the genotypic variation in shatter resistance. Through Genome-Wide Association Studies, we show that a large number of loci, including those that are involved in shattering in Arabidopsis, account for variation in shatter resistance in diverse B. napus germplasm. Our results indicate that genetic diversity for shatter resistance genes in B. napus is limited; many of the genes that might control this trait were not included during the natural creation of this species, or were not retained during the domestication and selection process. We speculate that valuable diversity for this trait was lost during the natural creation of B. napus. To improve shatter resistance, breeders will need to target the introduction of useful alleles especially from genotypes of other related species of Brassica, such as those that we have identified.     

Characters of Pod Anatomy Associated with Resistance to Pod-Shattering in Soybean

Seven characteristics of pod anatomy were studied for theirassociation with resistance to pod-shattering in 16 soybean[Glycine max (L.) Merrill] varieties and strains. The thicknessand length of the bundle cap on the dorsal side of the pod andpod-wall thickness were found to be significantly negativelycorrelated with the degree of pod-shattering. Further statisticalanalyses confirmed that these three anatomical characters werealmost equally important and could potentially serve as criteriafor the selection of resistance to pod-shattering. The identifiedtraits/sites in the pod represent sclerenchymous structuresand may provide the structural basis of resistance to pod-shatteringin soybean.Copyright 1995, 1999 Academic Press Pod, anatomy, shattering, soybean, Glycine max (L.) Merrill     

Fine mapping of a major quantitative trait locus that regulates pod shattering in soybean

Legumes represent the second most important family of crop plants, accounting for ~27 % of the world’s crop production. While some legumes are grown as forages or vegetables, most crop legumes are grown for harvesting their nutritious seeds. The legume seeds are contained in the pod, which is composed of a single seed-bearing carpel that, when matures, splits open along two seams, a process called pod dehiscence or pod shattering. Pod shattering before or during harvest causes yield losses of grain legumes. Moreover, the dominant shattering trait of the wild progenitors is a limiting factor for efficient introgression of value-added traits into elite breeding lines. Knowledge of the genetic mechanisms underlying pod shattering will facilitate breeding of shattering-resistant varieties, expedite introgression of agronomically favorable traits from wild species to elite breeding lines, and enrich our understanding of the evolution of seed dispersal and crop domestication in diverse crop species. Here we report fine mapping of a major quantitative trait locus (designated as qPDH1) that regulates pod shattering in soybean (Glycine max). A combination of linkage and association mapping allowed us to delimit the qPDH1 locus within a 47-kb region on chromosome 16. The data reported here will facilitate positional cloning of the underlying gene and the development of breeder-friendly genetic markers for marker-assisted selection in soybean.     

Genomic dissection of pod shattering in common bean: mutations at non‐orthologous loci at the basis of convergent phenotypic evolution under domestication of leguminous species

The complete or partial loss of shattering ability occurred independently during the domestication of several crops. Therefore, the study of this trait can provide an understanding of the link between phenotypic and molecular convergent evolution. The genetic dissection of ‘pod shattering’ in Phaseolus vulgaris is achieved here using a population of introgression lines and next‐generation sequencing techniques. The ‘occurrence’ of the indehiscent phenotype (indehiscent versus dehiscent) depends on a major locus on chromosome 5. Furthermore, at least two additional genes are associated with the ‘level’ of shattering (number of shattering pods per plant: low versus high) and the ‘mode’ of shattering (non‐twisting versus twisting pods), with all of these loci contributing to the phenotype by epistatic interactions. Comparative mapping indicates that the major gene identified on common bean chromosome 5 corresponds to one of the four quantitative trait loci for pod shattering in Vigna unguiculata. None of the loci identified comprised genes that are homologs of the known shattering genes in Glycine max. Therefore, although convergent domestication can be determined by mutations at orthologous loci, this was only partially true for P. vulgaris and V. unguiculata, which are two phylogenetically closely related crop species, and this was not the case for the more distant P. vulgaris and G. max. Conversely, comparative mapping suggests that the convergent evolution of the indehiscent phenotype arose through mutations in different genes from the same underlying gene networks that are involved in secondary cell‐wall biosynthesis and lignin deposition patterning at the pod level.