湖北省糯稻地方品种SSR遗传多样性研究

为评价湖北糯稻地方品种的遗传多样性,利用36对SSR标记对50份湖北地方糯稻品种进行PCR扩增和遗传多样性分析。结果表明,湖北糯稻地方品种的平均遗传多样性指数为0.710 7,多态信息含量平均为0.686 1,多样性较高。SSR标记聚类分析表明,湖北糯稻地方品种中遗传资源丰富,特别是籼粳糯稻成分互渗的品种,可广泛用于糯稻育种。     

Geographical, altitude and agro-ecological differentiation of isozyme and hordein genotypes of landrace barleys from Ethiopia: implications to germplasm conservation

An analysis of the variability of genes encoding six isozyme systems (15 loci) and two storage proteins (2 loci) in landrace barley from Ethiopia is reported. The materials consisted of populations collected from sites as low as 1650 and as high as 3750 meters, covering a wide range of agro-ecological conditions and geographical areas. Of the 17 loci 7 were polymorphic and 10 monomorphic when the 95% criterion of polymorphism was applied. Despite the disproportionate monomorphic loci, polymorphism was detected in all populations when this criterion is used. The populations were found to possess fairly low mean number of alleles per locus (A = 1.5), low mean value of expected heterozygosity (H = 0.134) and a fairly high mean percentage of polymorphic loci (P = 35.3%). The mean F_ST= 0.474 for the populations is typical of inbreeding species. The result indicated that allelic richness is concentrated in altitude class 3 (2500–3000 m) followed by altitude class 1 (<2000 m). Altitude class 2 (2000–2500) holds an intermediate place though it is the highest in terms of expected heterozygosity (H = 0.245). Higher genetic diversity is concentrated in some geographical regions such as Shewa, Arsi, Bale compared to others (Welo, Gamu Gofa, Gojam). Genetic differentiation among the agro-ecological zones was more profound than both among the altitudes and among regions. Correlation analysis between phenotypic diversity (Shannon-Weaver diversity index) and expected heterozygosity (H) for isozyme/hordein loci revealed non significant associations except with respect to agro-ecological zones. In general, it was detected that sites in highland areas in central and northern regions may be more desirable for in situ conservation than sites in peripheral regions in terms of isozyme/hordein diversity and current rate of varietal replacement.     

四川甘蓝型油菜地方种休眠特性的初步研究

对65份四川甘蓝型油菜地方种和1份对照种蜀杂6号作了收获前种子发芽试验,研究了四川甘蓝型油菜地方种的休眠特性。结果表明四川甘蓝型油菜地方种间休眠期差异显著,抗收获前发芽资源数量少;根据材料发芽进程和发芽指数进行聚类分析,参试材料被聚为4类:第一类为第1天发芽高峰类型,第二类为第2天发芽高峰类型,第三类为第1、2天发芽高峰类型,第四类为抗收获前发芽类型。本研究显示的甘蓝型油菜地方种的休眠特性和筛选到的抗收获前发芽的宝贵资源,将为甘蓝型油菜的抗收获前发芽生理研究和育种提供信息和材料。     

中国樱桃地方种质资源表型性状遗传多样性分析

以源自中国樱桃主产区7个群体,80份地方种质资源为试材,采用巢式方差及聚类分析法对其叶片、果实及果核26个表型性状进行多样性分析。结果表明:(1)质量性状之间存在较大的多样性差异,Shannon-Wiener多样性指数范围在0.61~1.64之间,其中果实形状、果皮颜色、叶片及果核剖面形状等表现出较高的遗传多样性。(2)数量性状无论是在群体间还是群体内均表现出极显著差异,14个数量性状的平均变异系数为9.93%,其中果柄长度的变异系数最高(24.80%),果核顶面观指数最低(6.61%)。在7个群体中,云南的种质材料变异系数最大,为12.92%;安徽的最小,为7.42%。(3)对14个数量性状的主成分分析表明,前5个主成分的累积贡献率达80.9434%,能反应数量性状的基本特征。(4)基于Nei’s遗传距离的聚类分析以及主坐标分析将80份材料分为2个大类,分布于山东、河南和安徽群体的种质资源聚为一类,为华北类群,分布于四川、云南、贵州和重庆群体的聚为另一类,为西南类群。研究结果表明不同地理分布群体的中国樱桃表型多样性存在差异,而这种遗传差异可能是由于来自不同的驯化位点而造成的。     

Screening of barley landraces by direct selection for crop improvement

Abstract

Barley (Hordeum vulgare L.) landraces display a high degree of variability in morphological and developmental traits, in disease resistance, and in protein content. Representatives of 29 barley landraces from southeast Turkey were collected from farmers’ fields, for a total of 800 accessions. The objectives of this study were to characterize these accessions over four years for morphological and agronomical traits to be used for future selection and breeding program. The observed variation between landraces was very large for all traits. In the first year of testing the accessions showed average grain yields ranging from 197–2225 kg ha^?1. After three years of selection, promising accessions were tested at two different geographical regions and using two different irrigation methods. One line was identified which significantly out-yielded the local landrace in all of the testing years and had a higher average yield than the check genotypes.     

STUDY ON THE EFFECTS OF NITROGEN DEFICIENCY ON GRAIN IRON AND ZINC CONCENTRATIONS OF LANDRACE AND BRED WHEAT VARIETIES IN CHINA

It has been reported that nitrogen (N) deficiency can significantly reduce grain iron (Fe) and zinc (Zn) concentrations in wheat. Here, we investigated the grain Fe (GFeC) and Zn (GZnC) concentrations of 42 Chinese wheat varieties grown in a field trial under low and high N conditions. Analysis of variance revealed that both GFeC and GZnC significantly differed among varieties and between N treatments, and significant interactions existed between variety and N treatment. The GFeC under the low N condition was 94.8% of that under high N condition, ranging from 79.4% to 112.7%; the GZnC under low N condition was 74.8% of that under high N condition, ranging from 59.5% to 102.5%. Wheat varieties with high GFeC and GZnC under both N conditions were identified, and this kind of varieties is desirable in breeding wheat with enriched Zn and Fe under a range of soil N conditions.     

山西小麦地方品种幼苗期抗旱性的鉴定

小麦幼苗长至二叶一心时,以200 g/L PEG-6000胁迫处理72 h,测定幼苗最大根长、根冠比、叶片相对含水量、相对电导率、SOD和POD活性以及MDA含量;采用模糊隶属函数与抗旱系数相结合的方法对各品种苗期的抗旱性进行综合分析;利用灰色关联度分析各个形态、生理指标与抗旱性的关系.结果表明:1)PEG胁迫下,9个小麦品种的最大根长、根冠比、相对电导率、SOD和POD活性及MDA含量均比对照高,而叶片相对含水量较对照低,而且差异均达到显著或极显著水平.2)利用隶属函数和抗旱系数相结合的方法对品种苗期抗旱性进行综合分析,各品种苗期的抗旱性表现依次为:白和尚头＞晋麦47＞竹杆青＞小红麦＞四月黄＞红皮冬麦＞灯笼红＞中麦9号＞忻县冬麦.3)SOD活性与苗期抗旱性关联度最大,其次为最大根长.     

西南地区玉米地方种质的表型特性分析

采用田间试验, 分析评价来自西南地区50个玉米地方品种的表型特征。西南地区玉米地方品种在各农艺、经济性状上存在极显著差异, 经济性状的变异程度较农艺性状的变异程度高;多数玉米地方品种植株和穗位较高, 平均株高和穗位高分别高达2.64 m和1.38 m。根据主成分分析结果, 从供试材料中选出10个表现较优的地方品种。表型性状的聚类结果不能反映玉米地方品种的地理来源。西南地区玉米地方品种蕴藏丰富的优良种质, 有必要加强这一种质的保护与利用。     

Genotype analysis of the wheat semidwarf Rht‐B1b and Rht‐D1b ancestral lineage

In wheat, semidwarfism resulting from reduced height (Rht)‐B1b and Rht‐D1b was integral to the ‘green revolution’. The principal donors of these alleles are ‘Norin 10’, ‘Seu Seun 27’ and ‘Suwon 92’ that, according to historical records, inherited semidwarfism from the Japanese landrace ‘Daruma’. The objective of this study was to examine the origins of Rht‐B1b and Rht‐D1b by growing multiple seed bank sources of cultivars comprising the historical pedigrees of the principal donor lines and scoring Rht‐1 genotype and plant height. This revealed that ‘Norin 10’ and ‘Suwon 92’ sources contained Rht‐B1b and Rht‐D1b, but the ‘Seu Seun 27’ source did not contain a semidwarf allele. Neither Rht‐B1b nor Rht‐D1b could be definitively traced back to ‘Daruma’, and both ‘Daruma’ sources contained only Rht‐B1b. However, ‘Daruma’ remains the most likely donor of Rht‐B1b and Rht‐D1b. We suggest that the disparity between historical pedigrees and Rht‐1 genotypes occurs because the genetic make‐up of seed bank sources differs from that of the cultivars actually used in the pedigrees. Some evidence also suggests that an alternative Rht‐D1b donor may exist.