Cross-Compatibility of Cultivated Adzuki Bean (Vigna angularis) and Rice Bean (V. umbellata) with Their Wild Relatives

The wild Ceratotropis species which occur in Japan consist of Vigna angularis var. nipponensis, V. nakashimae, V. riukiuensis and V. reflexo-pilosa. The main aim of the present study is to detect cross-compatibility of adzuki bean and rice bean with these wild relatives. The cross of V. nakasbimae with adzuki bean was successful in both directions and viable seeds were produced, while the cross with rice bean was not successful. V. riukiuensis is cross-compatible with adzuki bean and rice bean only when V. riukiuensis is used as male parent and the hybrid seeds showed normal germination. The cross between V. reflexopilosa and the two cultigens adzuki bean and rice bean did not succeed in either direction. The present results suggest that V. nakashimae and V. riukiuensis could be used as gene sources for the adzuki bean breeding programme through interspecific hybridization. Successful hybrids between adzuki bean and rice bean cannot easily be produced. However, since V. riukiuensis is cross-compatible with both adzuki bean and rice bean, V. riukiuensis could be useful as a bridge species between adzuki bean and rice bean.     

Introgression of productivity and other desirable traits from ricebean (Vigna umbellata) into black gram (Vigna mungo)

Crosses were performed to introgress genes for productivity and other desirable traits from ricebean (Vigna umbellata) into black gram (Vigna mungo). Crossability was very poor in black gram × ricebean crosses, and only two to nine true hybrid plants were obtained. Plant fertility was very poor in initial generations, but was improved gradually from F₂ onwards. Twenty‐four uniform progenies, bulked in F₇, were evaluated for yield potential. The percentage increase/decrease in yield ranged from ?35.48 to 50.31 over the check cultivar (‘Mash338’, female parent). All the progenies were found resistant to Mungbean yellow mosaic virus, Cercospora leaf spot and Bacterial leaf spot diseases. Overall, it was found that desirable traits such as high pod number, seed weight, productivity and resistance to diseases have been introgressed successfully into black gram from ricebean. A derivative line, KUG114, recorded yield superiority of 39.45% over the check cultivar ‘Mash338’ on the average of 14 multilocation research trials. It was released under the name ‘Mash114’ for cultivation in the Punjab state.     

Inheritance of flower and pod colour in cowpea (Vigna unguiculata L. Walp.)

Inheritance of flower colour and pod colour in cowpea (Vigna unguiculata L. Walp.) has followed a qualitative pattern. Purple flower colour is dominant over white flower colour, whereas black pod colour is partially dominant over white pod colour. A segregation ratio of 3 purple:1 white flowers in F₂ generations of two crosses indicated that white flower colour is controlled by a single recessive. Segregation ratio of F₂ 1 white:2 light black:1 black indicated that black pod colour is partially dominant over white pod colour and is governed by one gene. These results were further confirmed by backcross generations. White flower and pod colour are controlled by single recessive genes on separate chromosome. Gene symbols were assigned. This revised version was published online in July 2006 with corrections to the Cover Date.     

小豆种子活力的初步研究

早熟、丰产、抗逆性强的小豆新品种的选育以及大田生产中选用优质小豆种子均需要了解种子的活力水平。本研究选用3个小豆品种的新、陈种子,应用电导率法和发芽法进行种子活力测定,结果表明:小豆种子试样间在电导率、发芽势、发芽率、幼苗生长量和活力指数等方面均存在差异。不同品种间种子活力水平表现为红小豆LSH1>绿小豆>红小豆8937;同一品种的活力水平表现为新种子>陈种子;电导率值与种子活力指数呈显著负相关(r=-0.8667)。本研究认为,电导率法是测定小豆种子活力的一种简便、快速、有效的方法。     

理化诱变小豆京农6号突变体的鉴定

选用小豆品种京农6号种子,分别采用甲基磺酸乙酯(EMS)(0.5%、0.9%和1.4%处理12h和24h)、电子束(100、300、600Gy)、60Co-γ(400Gy)诱变处理,将处理后的种子种于大田,鉴定后代植株性状的变异。观察表明,EMS诱变的变异类型最丰富、60Co-γ射线次之、电子束产生的变异类型较单一。EMS处理小豆以浓度0.5%和0.9%处理24h为宜;0.5%EMS处理的粒色和荚色变异突出,有鲜红、黄白、绿白粒色和黑荚、褐荚、黑褐荚变异;0.9%处理的叶形变异突出,有鸡爪叶、剑叶、肾形叶、小密叶等突变类型;电子束诱变后,M2变异率分别为4.09%、3.64%和2.22%。400Gy60Co-γ射线处理种子,后代变异率为7.23%。通过两年的鉴定筛选,获得937个EMS诱变M3代株系,934个60Co-γ射线和电子束诱变M2代株系,已得到株高、叶形、叶色、粒形、粒色、荚色、无分枝、多分枝、叶簇生、分枝簇生、光叶、蔓生、有限结荚习性、株型松散、育性、成熟特性等突变体材料1490份。本研究为小豆基因遗传分析、基因定位与克隆及其进一步的基因功能分析奠定了基础,为小豆育种提供了重要的材料。     

Genetic diversity of the black gram [Vigna mungo (L.) Hepper] gene pool as revealed by SSR markers

In this study, 520 cultivated and 14 wild accessions of black gram (Vigna mungo (L.) Hepper) were assessed for diversity using 22 SSR markers. Totally, 199 alleles were detected with a mean of 9.05 alleles per locus. Wild black gram showed higher gene diversity than cultivated black gram. Gene diversity of cultivated accessions among regions was comparable, while allelic richness of South Asia was higher than that of other regions. 78.67% of the wild gene diversity presented in cultivated accessions, indicating that the domestication bottleneck effect in black gram is relatively low. Genetic distance analysis revealed that cultivated black gram was more closely related to wild black gram from South Asia than that from Southeast Asia. STRUCTURE, principal coordinate and neighbor-joining analyses consistently revealed that 534 black gram accessions were grouped into three major subpopulations. The analyses also revealed that cultivated black gram from South Asia was genetically distinct from that from West Asia. Comparison by SSR analysis with other closely related Vigna species, including mungbean, azuki bean, and rice bean, revealed that level of gene diversity of black gram is comparable to that of mungbean and rice bean but lower than that of azuki bean.     

Mapping of QTLs controlling epicotyl length in adzuki bean (Vigna angularis)

Epicotyl length (ECL) of adzuki bean (Vigna angularis) affects the efficiency of mechanized weeding and harvest. The present study investigated the genetic factors controlling ECL. An F₂ population derived from a cross between the breeding line ‘Tokei1121’ (T1121, long epicotyls) and the cultivar ‘Erimo167’ (common epicotyls) was phenotyped for ECL and genotyped using simple sequence repeats (SSRs) and single-nucleotide polymorphism (SNP) markers. A molecular linkage map was generated and fifty-two segregating markers, including 27 SSRs and 25 SNPs, were located on seven linkage groups (LGs) at a LOD threshold value of 3.0. Four quantitative trait loci (QTLs) for ECL, with LOD scores of 4.0, 3.4, 4.8 and 6.4, were identified on LGs 2, 4, 7 and 10, respectively; together, these four QTLs accounted for 49.3% of the phenotypic variance. The segregation patterns observed in F₅ residual heterozygous lines at qECL10 revealed that a single recessive gene derived from T1121 contributed to the longer ECL phenotype. Using five insertion and deletion markers, this gene was fine mapped to a ~255 kb region near the end of LG10. These findings will facilitate marker-assisted selection for breeding in the adzuki bean and contribute to an understanding of the mechanisms associated with epicotyl elongation.     

绿豆基因组SSR引物在豇豆属作物中的通用性

分子标记的种间通用性可降低其开发成本,提高利用效率,也有助于促进遗传研究较薄弱物种的分子遗传学研究。本文选取绿豆、小豆、豇豆及饭豆材料各3份, 分析1 205对新开发的绿豆基因组SSR引物在这些材料中的扩增效果,结果显示绿豆基因组SSR引物在豇豆、小豆和饭豆中的通用性比率分别为50.0%、73.3%和81.6%;多态性比率分别为4.1%、1.7%和1.5%;在4个种间均通用的引物469对。这些通用性SSR引物将有助于这4种食用豆类在多样性评价、连锁图谱的构建、基因定位及比较基因组学等方面的研究。     

Combining ability analysis and association of yield and yield components among selected cowpea lines

The study was carried out to determine combining ability and association of yield and yield components among crosses derived from seven selected cowpea (Vigna unguiculata (L.) Walp) parents. Twenty-one hybrids were generated from diallel crosses excluding reciprocals. Hybrids along with seven parents were studied for combining ability and phenotypic correlations for seed yield and eight yield components. The result indicated that the general combining ability (gca) and specific combining ability (sca) were significant for most characters indicating the importance of both additive and non-additive genetic components. Additive gene action was important for eight characters except pod number, whereas non-additive gene action was not important for nodule number and grain yield. Parental lines IT86D-716 and IT81D-985 were found to be good general combiners for grain yield and other traits. The most promising specific combiners for yield and yield components were from crosses including IT87D-697-2 × IT86D-716, IT88D-867-11 × IT86D-716, IT93K-624 × IT87D-697-2, and IT87D-697-2 × IT92KD-405-1. Significant positive phenotypic correlations were observed between seed yield with pod length (POL), number of pods per plant (PON), and number of seeds per pod (SPD). POL, pod number per plant, SPD, and grain yield were identified as the best selection criteria that could be used in cowpea breeding programs.     

不同种植密度对3个小豆品种植株形态及产量的影响

采用两因素随机区组设计,以直立型小豆品种冀红20、冀红21和唐红201602为材料,分析6个种植密度对不同小豆品种植株形态特征及产量性状的影响。结果表明,品种和种植密度对小豆形态特征和产量性状的影响较大;底荚高度和第一节间长随着密度的增加而增加,主茎节数、主茎分枝数、单株结荚数、单荚粒数和百粒重随着种植密度的增加而减小,产量随种植密度的增加呈先增加后减少趋势;相同品种不同种植密度间和相同种植密度不同品种间的产量差异极显著（F值分别为49.36、99.35）,品种与种植密度互作对产量的影响差异显著（F=3.91）。种植密度与株高、底荚高度呈极显著正相关,与第一节间长呈正相关,与茎粗、主茎分枝数和主茎节数呈极显著负相关。增加种植密度可增加小豆株高、底荚高度和第一节间长,有效减少主茎分枝数,有利于机械化收获。     

普通菜豆基因组SSR标记开发及在豇豆和小豆中的通用性分析

分子标记具种属间通用性可提高其利用效率,并降低标记开发成本。本研究基于Roche 454超高通量测序技术获得普通菜豆基因组测序结果,共开发了560个普通菜豆基因组SSR标记。利用2份普通菜豆品种对标记进行初步筛选,有421个标记能够有效扩增。用新开发的标记分析16份豇豆和16份小豆的通用性。结果显示,185个普通菜豆基因组SSR标记在豇豆中能有效扩增,通用性比率为43.9%;161个SSR标记在小豆中能有效扩增,通用性比率为38.2%;在豇豆和小豆中都能获得有效扩增条带的标记共138个;并且普通菜豆基因序列SSR标记在豇豆和小豆中的通用性比率高于基因间序列SSR标记。通用性标记的多态性分析表明,豇豆和小豆的多态性比率分别为34.0%和24.8%;且豇豆和小豆中基因间标记的多态性都比基因内标记的多态性高。上述通用性标记为豇豆属作物的多样性评价、连锁图谱的构建及基因定位等方面的研究提供了便利。     

Inheritance of pigmentation and pod shape in winged bean

Summary The inheritance of five qualitative character differences in winged bean was studied in two crosses. All five character pairs were based on a single gene difference with complete dominance of purple over green stem colour, purple over green calyx colour, purple over green pod wing colour, purple specks over green pod and rectangular over flat pod shape. Linkage was observed between stem and calyx colour and also pod wing colour and pod specks.     

Natural Outcrossing in Rice Bean

Natural outcrossing in rice bean (Vigna umbellata [Thumb.] Ohwi and Ohashi) was studied in the progenies of recessive plants in F generation of six crosses involving three loci — Ti (seed coat base colour), (seed coat mosaic) and Rr (seedling colour), The estimate of outcrossing (α) varied from 0.27 10 0.81 and the percentage of line showing outcrossing varied from 86.S to 100 and the outcrossing was non random.     

以地理来源分组和利用表型数据构建中国小豆核心种质

中国国家种质库里保存着4 877份小豆(Vigna angularis)种质资源,但仅有部分资源在小豆的改良中被利用。构建小豆核心种质, 不但能简化管理, 而且可以提高遗传资源在小豆改良中的利用效率。根据我国小豆的地理来源进行分组, 在分组的基础上利用表型数据, 以类平均法聚类构建了中国现有小豆核心种质, 共435份资源, 占资源总量的8.92%, 涵盖98.3%的表型变异类型, 控制不同性状表型相关的相互适应的遗传复杂性在核心种质中也得到了适当的保持。不同性状的均值t测验、方差F测验、表型频率分布、χ²测验等分析表明, 所构建的小豆核心种质可以作为整体资源的代表性样本, 在小豆种质资源的充分利用中将发挥重要作用。     

野赤豆在我国的地理分布

以往在我国,有的学者将野赤豆不合法命名为裂叶贼小豆和滇绿豆,或将其错误地鉴定为贼小豆,因之在中国无野赤豆的记载.通过作者的研究,赤豆起源于我国,并野赤豆不仅分布于辽宁,而且隔离分布于云南及广西.     

Estimation of additive, dominance and digenic epistatic interaction effects for certain yield characters in Vigna sesquipedalis Fruw

Inheritance of yield and yield contributing characters were investigated using generation mean analysis, utilising the means of six basic populations viz., P₁, P₂, F₁, F₂, BC₁P₁ and BC₁P₂ in four crosses of Vigna sesquipedalis. The analysis reiterated that the importance of dominance (h) gene effects for pod yield/plant and pods/plant as compared to additive (d) gene effects. However, significant and positive additive effects were noticed for pod yield/plant, pods/plant, pod weight and seed weight in different crosses. The three types of gene interactions (additive, dominance and epistasis) were significantly involved for pods/plant in cross KU 7 ×KU 8. Among the digenic epistatic interactions, both additive ×additive (i) and dominance × dominance (l) contributed more for pod yield/plant and pods/plant, however, it varied among the crosses. Populations having earliness can be developed as indicated by reducing dominance effects. Pedigree selection and heterosis breeding is suggested to exploit the fixable and non fixable components of variation respectively in Vigna sesquipedalis. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effects of selection in tetraploid green gram varieties

A comparative study of the effect of tetraploidy in three varieties of green gram (Phaseolus aureus Roxb.) and selection of plants with high, medium and low vigour showed that the reduced leaflet size and height at the time of flowering can be considerably improved by selection. It appeared that the diploid level can be approached or even exceeded.The reduced fruit setting can also be improved considerably but not the size of fruits and number of seeds per pod. The increased seed weight was further improved in two varieties. The increase in protein content of the tetraploid seeds was greatest in the variety with the lowest protein content at the diploid level.Though for vegetative growth selection alone would suffice to bring the tetraploids up to the diploid level, if not higher, the reduced fruit and seed setting, though responding well to selection, are unlikely to be overcome unless other breeding methods are introduced.     

小豆种子的萌发特性研究

本研究通过小豆种子的吸水试验、发芽试验及田间试验 ,对小豆种子的萌发特性进行了研究。在参试的 4个小豆品种中 ,白小豆的发芽势和发芽率最高 ,其次是绿小豆和红小豆 ,冀红小豆 4号最低。结果表明 :小豆种子的发芽势、发芽率与其吸水速率、吸水量密切相关。     

QTL mapping of pod tenderness and total soluble solid in yardlong bean [Vigna unguiculata (L.) Walp. subsp. unguiculata cv.-gr. sesquipedalis]

Yardlong bean [Vigna unguiculata ssp. unguiculata cv.-gr. sesquipedalis] is an important vegetable legume, particularly in Asia. Tenderness and sweetness of fresh pods are the key factors in deciding the commercial acceptance of yardlong bean. We report here for the first time quantitative trait loci (QTL) mapping of these traits from crosses between the yardlong bean accession JP81610 and wild cowpea (V. unguiculata ssp. unguiculata var. spontanea) accession JP89083. Two SSR-based linkage maps developed from BC₁F₁ [(JP81610?×?JP89083)?×?JP81610] and F₂ (JP81610?×?JP89083) populations were used for QTL analysis of pod tenderness and total soluble solid (TSS) content. Composite interval mapping (CIM) identified three QTLs for pod tenderness with phenotypic variance explained (PVE) of 5.6?C50?% and alleles from JP81610 increased the tenderness. CIM detected two QTLs for pod TSS with PVE of 7 and 9?%, and alleles from JP89083 increased TSS. Locations of these QTLs were compared with those of QTLs controlling domestication-related traits identified in the same populations. All QTLs for pod tenderness co-localized with QTLs for pod length. QTLs for pod TSS co-located with QTLs for pod dehiscence and/or pod length. The implications of these QTLs in breeding new yardlong bean and cowpea cultivars are discussed.     

Interspecific hybridization between rice bean (Vigna umbellata) and its wild relative (V. minima): Fertility-sterility relationships

Summary The pre-and post-fertilization barriers in the interspecific crosses between Vigna umbellata and V. minima were investigated. In the reciprocal crosses (V. minima as the parent) the entry of pollen tubes into the ovary was delayed by about 4 h, and no seed set was observed. However, no pre-fertilization barriers were encountered in crosses involving V. minima as the parent and V. umbellata as the parent (normal cross). The delay/absence of divisions in the endosperm and the failure of embryo to divide were the post-fertilization barriers responsible for somatoplastic sterility in normal crosses which yielded a few hybrid seeds. The hybrid seeds showed poor germinability. The F₁ hybrids were intermediate between the parents in most morphological characters, and are completely sterile for pollen. Backcrossing of F₁ hybrid with both the parents did not restore fertility in the progenies. V. minima is considered as the tertiary gene pool of the rice bean.