烟草F2:3家系7个主要产量性状的遗传变异分析

在福州与龙岩2个环境下,以烤烟品种‘台烟7号’与白肋烟品种‘白肋21’为亲本构建的127个F2:3家系为材料,对株高、叶长、叶宽、叶片数、分枝数、生育期和茎叶夹角7个性状进行遗传分析。结果表明：2种环境条件下,F2:3家系大部分性状分离明显,且基本符合正态分布,为多基因控制的数量性状,是一个较为理想的QTL作图群体。F2:3家系内各性状都存在不同程度的差异,分枝数变异系数最大,叶长、生育期变异系数最小,表明受环境影响较大。由各性状之间的相关分析得出：在2种环境下,21对性状中均有13对达到极显著水平,其中大部分性状相关系数均大于0.3,说明F2:3群体主要产量性状间具有复杂的相关关系。     

基于温热玉米F2:3家系产量相关性状的遗传解析

以Suwan代表性自交系T 32(母本)和PB群核心自交系齐319(父本)为亲本,获得128份F2:3家系,并对该群体的8个产量相关性状进行了正态性检验与相关性分析.结果表明,群体产量相关性状变异较大,各性状呈现近似正态分布.百粒重与粒长、粒宽呈极显著正相关,穗行数与粒宽呈极显著负相关;穗长与穗行数、行粒数相关性显著;...     

2个小麦种质材料育种相关性状的初步分析

对引自德国的品种‘16亲10188’、大穗抗病种质‘YB’等2个小麦种质的育种特性进行初步鉴定。利用西南麦区主栽品种和地方品种分别与其杂交组配,并对其F1代及其亲本进行产量、抗病相关性状的调查。‘16亲10188’具有矮秆、多粒、抗条锈病、抗白粉病的特性,在F1组合中,其矮秆表现为部分显性,高穗粒数表现为隐形或部分显性,条锈病抗性表现为显性,白粉病抗性表现为隐性;‘YB’为大穗、寡分蘖、抗条锈病、抗白粉病材料,其长穗表现为部分显性,寡分蘖表现为隐性,穗粒数、粒重性状在F1中表现为杂种优势,抗白粉病表现为隐性。‘16亲10188’的降秆、条锈病抗性在育种中可以进行早代选择,高穗粒数、抗白粉病性状可以在高代系群体中进行选择;‘YB’的F1组合在产量上表现出显著的杂种优势,可作为杂交小麦育种的优良亲本。     

小麦生育期性状与产量性状的相关与通径分析

通过对来自全国各地的48个小麦品种生育期性状与产量性状的相关与通径分析，结果表各生育期性状与千粒重、穗粒重等主要产量构成因素和产量基本呈显著正相关，与退化小穗数极显著负相关。全生育期天数对产量的直接影响最大（p4y=0.5671),达极显著水平；“出苗－抽穗”天数对产量的直接影响负向显著（p1y=-0.2554),但经全生育期天数对产量有一个较大的正向间接作用（p1→4→y=0.4499);“抽穗－开花”天数以及“开花－成熟”天数对产量直接影响均不显著。     

小麦产量与若干品质性状的相关研究

长期以来 ,我国小麦生产一直偏重追求产量。随着生产条件的改善与麦作科技水平的不断提高 ,小麦生产已在数量上暂告别了短缺 ,出现了过剩和积压现象 (普通小麦品种及品质差的品种 )。与之相反的是 ,我国每年还需进口相当数量的优质小麦 (90年代以来每年约 10 0 0万ｔ) ,以适应我国人民生活水平提高对小麦面粉制品的品质要求。因此大力加强优质小麦的研究与生产 ,既是我国目前农业结构调整的需要 ,更是中国“入世”后 ,在世界贸易市场上增强自身竞争力的需要。培育优质品种 ,选择适宜生态地区种植并配套规范化栽培措施 ,使优质与产量达到较高…     

小麦高产育种中产量性状的相关及其改良

把山东省及黄淮麦区建国以来小麦品种产量性状的演变与当前高产新品种（系０相应性状的研究结合起来，从性状的灰色关联度、选择指数、多元回归及相关通径分析等不同角度进行了综合分析。随着品种产量水平的提高，穗重发挥着日益重要的作用，而影响穗重的主要因素千粒重。不同类型的高产可以有不同的产量构成模式。对于如何协调产量性状之间的关系，抓住改良重点，提高选择效率等问题进行了讨论。     

基于温热玉米F2∶3家系的株型相关性状遗传分析

株型在玉米种质改良过程中扮演着重要的角色,理想株型是提高玉米种植密度的关键因素,可提高产量。本研究以热带玉米自交系QR273(母本)和温带自交系HCL645(父本)为亲本,通过杂交和自交获得160份F2:3家系。分析该群体的株高、穗位高、叶夹角、雄花分枝数的变异情况和相关性,旨在剖析玉米种质改良过程中株型相关性状的选择方向。结果表明,该群体株型相关性状变异较大,各性状呈现近似正态分布。株高、穗位高、雄花分枝数之间呈显著正相关,其中株高与穗位高相关系数最高,为0.672,即株高越高穗位越高,一定程度反映了株型性状玉米人工选择过程中的指示作用。     

小麦产量与农艺性状的相关分析和通径分析

以23个小麦品系为研究对象,采用随机区组试验,设3个重复,对不同农艺性状与产量进行相关性和通径分析,分析参试品系的农艺指标与产量的关系。结果表明,产量三要素与产量的相关系数和通径系数都为穗数>穗粒数>千粒重,穗数与产量之间呈显著正相关,穗粒数、千粒重与产量之间关系呈负相关,但相关性不显著。收获指数、生物产量与子粒产量分别呈极显著和显著正相关,所有品系都有较高的生物产量和收获指数;供试品系的产量与株高和株高构成指数呈正相关,穗长、单穗重与产量之间呈负相关,但相关性不显著。     

干旱调控下马铃薯抗旱相关性状的遗传变异分析

以敏感型品种大西洋和耐旱型品种定薯1号为亲本构建的185个F1分离群体为材料,研究了正常灌溉和干旱胁迫2种环境条件下,该群体株高、茎粗、主茎数、分枝数、单株结薯数、单株薯重共6个数量性状的遗传特点。结果表明:2种环境条件下,分离群体各性状分离明显,且基本符合正态分布,表现为数量性状遗传特点,是一个较为理想的QTL作图群体。分离群体在干旱胁迫和正常灌溉条件下相关性状的差异主要是由于环境条件引起的。     

水、旱条件下小麦苗期部分农艺性状的遗传分析

为研究水分胁迫对小麦幼苗部分农艺性状的影响,分析这些性状与干旱胁迫的关系。以‘青麦6号’和‘烟农24’杂交形成的F2:3群体为材料,采用主基因+多基因混合遗传模型对其进行遗传分析。水、旱2种条件下,根长和根鲜重均为1对加性-显性效应主基因模型;茎鲜重、茎干重、根干重、根茎鲜重比和根茎干重比的最适遗传模型不同。干旱胁迫条件下,茎鲜重主基因遗传率为37%,茎干重、根长、根鲜重、根干重、根茎鲜重比及根茎干重比主基因遗传率分别是51%、81%、74%、56%、50%、68%。茎鲜重、茎干重、根干重等性状,尽管检测到主基因,但在水旱条件下遗传模型不同,可进一步研究其遗传规律。     

Genetic variation in wheat cadmium accumulation on soils with different cadmium concentrations

Cadmium (Cd) accumulation in wheat genotypes of spring bread wheat (Triticum aestivum L.) and spring durum wheat (Triticum turgidum var. durum) was studied in field trials every third week throughout the growing season. The study was carried out in Sweden on three different soils and during two growing seasons. The results showed that the genetic variation in shoot and grain Cd accumulation remained consistent, regardless of soil type or growing season. In addition, it was possible to select the genotype that accumulated most Cd already at the beginning of the growing season, since this genotype also accumulated most Cd in the vegetative tissues of the shoot. These results indicate that it is possible to identify genotypes that accumulate most Cd in the grain at an early plant development stage. High Cd concentrations in the shoot were also observed to give high Cd concentrations in the grain. This indicates that the regulatory mechanism for grain Cd accumulation is not located in the shoot, but in the root or as a feature of root Cd uptake. The soil material and the soil solution at all three sites were analysed for strongly bound Cd (as extracted with 2 m HNO₃), more easily plant‐available Cd (as extracted with ammonium lactate), pH, organic matter, clay content and conductivity. None of these parameters was clearly correlated to the Cd concentration in the grain.     

玉米F2群体轴部相关性状的数量遗传分析

本研究采用遗传模型预测的方法,探究玉米轴部性状的遗传机理,以期为育种家指明育种方向,提高育种效率。以FBHJ和MBUB两亲本组配的含390个家系的F₂群体为材料,利用植物数量分离分析软件包中的F₂单世代分析方法,对其穗轴长、粒长、穗轴粗、粒宽、穗轴重、百粒重、粒厚等7个轴部相关性状进行数量遗传分析、相关分析以及回归分析。结果表明,穗轴粗、粒长、粒宽3个性状最适遗传模型为A-0,即无主基因遗传;穗轴重和粒厚受2对主基因控制,主基因存在加性-显性-上位性,符合B-1模型;穗轴长和百粒重由1对主效基因控制,最适模型分别为A-1、A-3,各模型主基因遗传率介于28.37%～59.11%,其中百粒重性状的遗传率最大。各性状均与百粒重呈极显著正相关。百粒重(Y)对其他农艺性状的回归方程为Y=-57.126+0.176X₁+3.069X₂+2.890X₃+5.108X₄,拟合度为0.723。通径分析中粒宽的间接作用和粒长的直接作用表现最大。这一研究结果为玉米轴部性状的遗...     

小麦重要产量性状的主基因+多基因混合遗传分析

以单株产量等为代表的重要性状是选育小麦高产良种的主攻目标性状,分析小麦重要产量性状的数量遗传特性,为深入研究其遗传机制提供依据。本研究选用品冬34为母本(P₁)和BARRAN为父本(P₂)配置杂交组合,在2年4个环境下应用主基因+多基因混合遗传模型方法对该组合单世代(P₁、P₂、RIL_7:8、RIL_8:9)单株产量、千粒重、株高、穗下节间长、旗叶上节间长和分蘖数进行遗传及相关分析。结果表明,除千粒重和分蘖数外,其余性状间均显著或极显著相关,穗下节间长与旗叶上节间长平均相关系数达0.91 (P≤0.001)。最优遗传模型对于单株产量是4对加性上位性主基因+多基因遗传模型,其主基因加性效应值分别为3.78、2.89、–6.18和0.15,多基因遗传率为86.23%;对于千粒重是2对互补作用主基因+加性效应多基因混合遗传模型,多基因加性效应值是22.37,主基因遗传率为66.96%,多基因遗传率为28.25%;对于株高是2对累积作用主基因+加性作用多基因混合遗传...     

Genetic variation in drought resilience-related traits among wheat multiple synthetic derivative lines: insights for climate resilience breeding

Twenty-four wheat lines, developed by Aegilops tauschii Coss. introgressions and previously selected for heat or salinity stress tolerance, were evaluated under a drought-rewatering-drought cycle for two years. The objective was to select breeding lines that are resilient to more than one abiotic stress. The experiment was designed in alpha lattice with three replications. Drought was imposed by withholding water during flowering. The results revealed considerable genetic variability in physio-agronomic traits, reflecting the variation in the introgressed segments. High heritability estimates (above 47%) were recorded for most traits, including days to 50% heading, plant height, and thousand-grain weight, indicating the genetic control of these traits which may be useful for cultivar development. The trait-trait correlations within and between water regimes highlighted a strong association among the genetic factors controlling these traits. Some lines exhibited superior performance in terms of stress tolerance index and mean productivity compared with their backcross parent and elite cultivars commonly grown in hot and dry areas. Graphical genotyping revealed unique introgressed segments on chromosomes 4B, 6B, 2D, and 3D in some drought-resilient lines which may be linked to drought resilience. Therefore, we recommend these lines for further breeding to develop climate-resilient wheat varieties.     

新疆冬小麦品种农艺及产量性状遗传多样性分析

Grain yield is one of the most important goals in wheat breeding, and agronomic or yield-related traits can directly reflect the characteristics of varieties. In order to determine the evolution of genetic diversity in agronomic traits of Xinjiang winter wheat varieties and their adaptabilities to different ecological environments, 134 winter wheat landraces and 54 moderns bred varieties from Xinjiang were selected for agronomic trait investigation. They were planted in three different ecological environments (Urumqi and Yining in Xinjiang province, and Tai’an in Shandong province) for two consecutive growth seasons, and nine agronomic and yield-related traits were surveyed and analyzed. The estimated broad sense heritability of nine agronomic and yield traits was in descending order: plant height > grain width > grain length/width ratio > spike length > spikelet number > thousand- kernel weight > grain number per spike > grain length > fertile spikelet number. Correlation analyses of nine agronomic and yield traits showed that these traits were correlated with each other. It was found that the plant height, spike length and grain length/width ratio of landraces were higher than that in modern bred varieties, but the grain number per spike, thousand kernel weight, grain length and grain width in landraces were less than that in modern bred varieties. However, the correlation coefficient of these nine traits was higher in modern bred varieties than that in landraces. These variations reflected the evolution of Xinjiang winter wheat varieties in agronomic traits in recent years. This study may provide important information for breeders to select the breeding parents in different winter wheat regions.     

F2:3设计全基因组标记的Bayesian分析

数量性状的遗传率低时,常采用F_2:3设计进行遗传分析,但往往忽略异质家系内QTL的混合分布特性。同时,用多QTL模型检测QTL会提高QTL检测的功效。因此,本文在利用F_2:3设计异质F_2:3家系内QTL混合分布特性基础上,提出F_2:3设计全基因组多标记联合分析新方法。该方法充分利用了异质F_2:3家系内的QTL混合分布,并采用多QTL遗传模型。Monte Carlo模拟研究表明,新方法能获得精确的QTL效应和位置的估计。此外,还比较了QTL效应抽样的两种策略。研究表明,新策略能显著提高QTL检测的功效。     

Genetic diversity of hexaploid wheat cultivars estimated by RAPD markers, morphological traits and coefficients of parentage

Estimates of genetic diversity can be based on different types of data. The aim of this research were to study genetic diversity among Croatian wheat cultivars by random amplified polymorphic DNA (RAPD) markers, morphological traits and pedigree records; to analyse differences between wheat cultivars from two breeding centres; and to evaluate usability of RAPD markers for estimation of genetic diversity among wheat cultivars in comparison with morphological traits and pedigree record data. Studies were conducted on 14 wheat cultivars and breeding lines from two breeding centres in Croatia. For the RAPD analysis 36 primers were screened and the 14 most polymorphic ones yielded 341 polymorphic bands. Twelve morphological traits were used for morphological analysis. Pedigrees were composed of seven generations of ancestors. RAPD markers showed a high level of polymorphism among the cultivars examined and the breeding lines. No significant correlations were observed among the methods tested.     

Genetic variation and interrelationships of agronomic characters in landraces of bread wheat from southeastern Iran

There is renewed interest in wheat landraces as important sources of genetic variation for agronomic characters. Fifty-three pure lines of bread wheat (Triticum aestivum L.) derived from seven landraces collected from southeastern Iran were used to estimate genetic variation and heritability for 13 developmental and quantitative characters. Path-analysis was used to partition the genetic correlations between grain yield and six grain yield-related traits. Mean values of landraces were also compared with three improved cultivars from California and Iran. Genotypic differences among the landraces and among the pure lines collected from the landraces were highly significant for all characters considered. Compared with the modern cultivars, the landrace genotypes were, on average, later in days to heading and taller than the cultivars but had lower values for number of grains per spike, 1000-grain weight, grain yield and harvest index. Some landrace genotypes were similar to the modern cultivars for grain yield. Moderate to high genetic variation was displayed by number of grains per spike, number of spikes per plant, 1000-grain weight, and harvest index. The heritability estimates ranged from 59% for grain yield to 99% for days to anthesis. Expected genetic advance (as % of the mean) was ≈34% for number of spikes per plant, number of grains per spike, and 1000-grain weight. Days to heading and to anthesis correlated positively with number of spikes per plant, shoot biomass, and straw biomass but negatively with number of grains per spike and harvest index. The strong direct effect of number of spikes per plant on grain yield was completely counterbalanced by its indirect negative effects via number of grains per spike and 1000-grain weight. Number of grains per spike and 1000-grain weight were positively correlated with grain yield, and they had large direct effects. These two characters, however, were negatively correlated and exhibited a substantial counterbalance effect via one another and via number of spikes per plant. The landraces could be improved by intercrossing the promising genotypes identified in this study, with simultaneous selection for earliness, fewer number of spikes per plant, greater number of grains per spike and heavier grains. For further improvement, crossing programs between the landraces and introduced germplasm may be necessary. This revised version was published online in July 2006 with corrections to the Cover Date.