水稻地方品种与改良品种内部遗传异质性的比较分析

云南是亚洲栽培稻起源中心和多样性中心,不乏栽培历史悠久的地方品种,它们是有效保护和持续利用作物种质资源的重要研究材料。本研究以3个栽种历史悠久的水稻元阳地方品种(白脚老粳、红脚老粳和月亮谷)以及3个曾经在当地推广但迅速被淘汰的改良品种(楚粳26、楚粳27和合系22)为材料,利用24对微卫星(SSR)引物对其内部遗传异质性进行了比较分析,共检测出103个等位基因,各引物在元阳地方品种中检测到的等位基因数均多于改良品种,后者丧失部分等位基因。可见元阳地方品种的内部异质性较高,带来的选择性压力较小,为地方品种提供了宽泛的适应性。     

长江中下游麦区小麦地方品种幼苗耐镉性的差异

为了明确不同小麦地方品种耐镉（Cd）性的差异,采用水培方法,测定了长江中下游麦区32个小麦地方品种的苗期生长指标、叶绿素含量、荧光参数和光合参数,并对参试品种的Cd耐性进行了比较和聚类分析。结果表明,32个小麦地方品种镉耐性指数变异系数为10.4%～49.4%,耐Cd性差异较大。根据耐性指数可将参试品种分成耐镉型（7个）、较耐镉型（4个）、中间型（6个）、镉较敏感型（8个）、镉敏感型（7个）5组。     

Genotypic response of common bean to natural field populations of bean fly (Ophiomyia phaseoli) under diverse environmental conditions

Bean fly is a significant pest of common bean in semi-arid areas of East Africa. Apart from inadequate moisture in the dry land, bean fly simultaneously contributes negatively thereby adversely affecting bean productivity. The objectives of this study were to (1) identify sources of resistance to bean fly available in landraces, (2) confirm stability of host plant resistance in drought stress and (3) determine the effect of drought stress and seasonal variation on common bean genotypes in relation to bean fly attack for adaptability to the semi-arid areas of East Africa. Sixty four genotypes including landraces, bean fly resistant lines and local checks were evaluated for seed yield, 100-seed weight, days to maturity, plant mortality and pupae in stem in an alpha lattice design with two replications. This was under drought stressed (DS) and non-stressed (NS) environments and two treatments (insecticide sprayed and natural infestation) for three cropping seasons between 2008 and 2009. Genotypes differed in their reaction to natural bean fly attack under drought stressed (DS) and non-stressed (NS) environments over different cropping seasons. However, the effect of bean fly appeared to vary between the long rains (LR) and short rains (SR). It was observed that an increase in number of pupae per stem resulted in a higher plant mortality. The range of seed yield was from 345 to 1704 kg ha⁻¹ under natural infestation and from 591 to 2659 kg ha⁻¹ under insecticide protection. Seed yield loss ranged from 3 to 69%. The resistance of most of the bean fly resistant lines seemed to break down in presence of DS owing to their dismal performance. Screening of genetic resources in common bean to breed for host plant resistance to bean fly offers high potential of success if researchers take full advantage of the diversity available within the landraces.     

Recovering Portuguese Rice Landraces by Marker-Assisted Selection

Rice （Oryza sativa L.） was domesticated in Asia and brought to Europe （Mediterranean region） by returning members of Alexander the Great＇s expedition to India （324 B.C） （Khush, 1997）. In Portugal, rice was introduced by the Moors in the 10th century, and therefore has a long cultural tradition. Among the European countries, Portugal has the highest rice consumption per capita, with approximately 22.4 kg/capita/year, while the second country, Spain, only consumes 10.4 kg/capita/year （data from http：//www.fao.org referring 2004）. In 2005, the total rice area harvested was 23 060 hm2, distributed on the four main river beds： Mondego, Tejo, Sado and Sorraia. Presently Portugal produces nearly 56% of the internal demands, to meet the national needs, importation reached 6.8 xl07 kg in the year 2005 （data from http：//ania.pt）. About 80 percent of the rice area in Portugal is cultivated with japonica varieties and the rest is cultivated with indica-like varieties. These indica-like varieties are being cultivated particularly in the Southern regions, with much acceptance by the farmers due to their higher yields. Presently all Portuguese commercial varieties are either from Italy or from overseas.     

Identification of Italian landraces of bean (Phaseolus vulgaris L.) using an image analysis system

Colour, shape and size of whole seeds and their spots of some Italian landraces of bean (Phaseolus vulgaris L.) were measured using a specifically developed macro, based on image analysis library KS-400 V 3.0 (Carl Zeiss, Germany).     

Inheritance of ‘domestication’ traits in bambara groundnut (Vigna subterranea (L.) Verdc.)

Controlled crosses in bambara groundnut were attempted between a range of thirty-six bambara groundnut landraces (thirty domesticated (V. subterranea var. subterranea) and six wild (V. subterranea var. spontanea)). Ten F₁ seed were produced. Of these, eight germinated producing F₂ populations. On seed set, four populations could be unambiguously confirmed as true crosses by F₃ seed coat colour. A single F₂ population, derived from a domesticated landrace from Botswana (DipC; female parent) crossed with a wild accession collected in Cameroon (VSSP11; male parent) was used to study a range of agronomic and domestication traits. These included; days to emergence, days to flowering, internode (fourth) length at harvest, number of stems per plant, leaf area, Specific Leaf Area (SLA), Carbon Isotope Discrimination (CID), 100 seed weight, testa colour and eye pattern around the hilum. On the basis of variation for internode length and stems per plant, 14 small F₃ families were selected and grown under field conditions to further investigate the genetic basis of the ‘spreading’ versus ‘bunched’ plant character, a major difference between wild and cultivated bambara groundnut. Results presented suggest that traits including leaf area, SLA, CID and 100 seed weight are controlled by several genes. In contrast, the variation for traits such as internode length, stems per plant, days to emergence and seed eye pattern around the hilum are likely to be under largely monogenic control. The results of this work are discussed in relation to the domestication of bambara groundnut.     

Agro-morphological diversity of Spanish traditional melons (<Emphasis Type="Italic">Cucumis melo</Emphasis> L.) of the Madrid provenance

The variability of 14 landraces belonging to a Madrilean village historically specialized on melon cultivation, Villaconejos, was evaluated based on 58 quantitative and qualitative morphological traits. These landraces were compared to a reference array composed of 14 accessions which represented the main varieties cultivated in Spanish fields. Individual data related to plant, fruit, seed and phenology have been analysed using a multivariate analysis. This analysis showed intra- and inter-varietal diversity, as emphasized the most discriminant morphological traits in order to define similarities. Villaconejos accessions were morphologically distinct from the reference accessions (RA). Only the landraces belonging to Piel de Sapo market class showed common morphological affinities with the RA, grouping with them. The majority of Villaconejos traditional varieties clustered in five different groups, with no RA within, showing distinctive morphological singularities not described previously. Two of these groups showed some particularities in fruit traits, which are appreciated as quality marks for Spanish consumers. These results indicate that these accessions must be conserved as valuable genetic resources to enrich the Inodorus genetic bases for future breeding proposes worldwide. Furthermore, it should be considered the opportunity of promoting their cultivation under the shelter of a Protected Geographical Indication as a high quality melon. Finally, the discovering of such a high variability presented in a very small area, gives a clue for focusing, with an elevated probability of success, future surveys in similar ancestral European villages which in the past times, also supplied more populated cities with their farming products.     

Relationship between yield and mineral nutrient concentrations in historical and modern spring wheat cultivars

The diet of approximately three billion people worldwide is nutrient deficient and most of the world’s poorest people are dependent on staple food crops as their primary source of micronutrients. One component of the solution to nutrient deficiencies is collaboration among plant breeders, cereal chemists and nutritionists to produce staple crop cultivars with increased mineral nutrient concentration. Sixty-three historical and modern wheat cultivars were evaluated for grain yield and concentration of calcium, copper, iron, magnesium, manganese, phosphorus, selenium, and zinc. While grain yield has increased over time, the concentrations of all minerals except calcium have decreased. Thus a greater consumption of whole wheat bread from modern cultivars is required to achieve the same percentage of recommended dietary allowance levels contributed by most of the older cultivars. The decrease in mineral concentration over the past 120 years occurs primarily in the soft white wheat market class, whereas in the hard red market class it has remained largely constant over time. This suggests that plant breeders, through intentional selection of low ash content in soft white wheat cultivars, have contributed to the decreased mineral nutrient concentration in modern wheat cultivars. These results contradict the theory that there exists a genetically based, biological trade-off between yield and mineral concentrations. Therefore, using the abundant variation present in wheat cultivars, it should be possible to improve mineral concentrations in modern cultivars without negatively affecting yield.     

13个玉米地方种质的配合力分析

选用5个自交系为测验种,采用不完全双列杂交遗传交配设计,对四川盆地及盆周山区13个玉米地方种质的配合力进行了分析。结果表明：屏山大黄、筠连血丝和筠连大白马牙具有较大的利用潜势;13个地方种质可分为5个初级杂种优势群。根据特殊配合力(SCA)效应及产量表现,确定了旅大红骨×地方种质、热带种质×地方种质和PA亚群×地方种质是利用地方种质组配的强优势组合模式。     

太湖流域糯稻地方品种资源农艺性状分析

为了充分利用地方资源有利基因拓展现代育成品种的遗传基础和改良目标性状,本研究利用15个主要农艺性状对135个太湖流域糯稻地方品种资源进行了分析。结果表明,晚熟、株高和穗颈长偏高、着粒密度和产量偏低为太湖流域糯稻地方品种的主要特征。性状的变异系数范围为3.42%~35.01%,单株产量、单株有效穗、每穗总粒数、每穗实粒数、穗颈长短、着粒密度等6个性状居前列。主成分分析显示,PC1-PC5能够解释总体70.4%的变异,而每穗总粒数、每穗实粒数、着粒密度、单株有效穗、株高、千粒重、单株产量等7个性状因具有高的特征向量值,为分析太湖流域糯稻地方品种资源的重要性状。以主成分分析中提取的5个公因子进行聚类分析,可将研究材料分为14类,其中第Ⅰ、Ⅸ、ⅩⅣ和Ⅻ类品种有利性状突出,是改良当地糯稻品种的极有用的种质资源。产量构成因子和单株产量的偏相关分析表明,太湖流域糯稻地方品种对产量的贡献主要是单株有效穗和每穗粒数,这也是地方品种亟待改良的重点。研究还发现,同名异种现象十分普遍。