Inheritance of equine sarcoid disease in Franches-Montagnes horses

The mode of inheritance for susceptibility to equine sarcoid disease (ES) remains unknown. The objectives of this study were to analyse a large sample of the Franches-Montagnes (FM) horse population and investigate the heritability and mode of inheritance for susceptibility to ES. Horses were clinically examined for the presence of sarcoid tumours. A standardized examination protocol and client questionnaire were used and a pedigree- and subsequent segregation-analysis for the ES trait performed. To investigate the mode of inheritance, five models were evaluated and compared in a hierarchical way.The analyses reveal that variation in susceptibility to ES is best explained by a model incorporating polygenic variation. The possible effect of a major gene, such as specific equine leukocyte antigen alleles, is unlikely, but cannot be ruled-out entirely. The heritability of the phenotype on the observation scale for the trait ‘affected with ES’ was estimated to be 8%. A corrected value for the heritability on a liability scale was estimated at 21% and it is therefore possible to estimate breeding values for ES. The arguments against the practical implementation of an estimated breeding value in a multifactorial condition like ES are discussed.     

中国对虾生长性状的遗传力和遗传相关估计

[目的]对中国对虾生长性状的遗传力和遗传相关进行估计,为中国对虾的选择育种提供基础依据和技术参数。[方法]采用人工授精技术建立了51个全同胞家系（包括35个半同胞家系）,分别测定了中国对虾150日龄时各家系的体长、头胸甲长、腹节长和体重。应用数量遗传学原理,采用方差、协方差分析的方法,研究了中国对虾150日龄时生长性状的遗传力及性状间的遗传相关和表型相关。[结果]中国对虾体长遗传力的估计值在0,36—0．51,头胸甲长的遗传力估计值在0．14—0．24,腹节长的遗传力估计值在0．25～0．50,而体重的遗传力估计值在0．04～0．29。中国对虾各生长性状表现出高的正相关,其中体重和腹节长的遗传相关最大（为0．92）,其次为体长和腹节长（0．91）、体长和体重（O．88）、体重和头胸甲长（O．87）、腹节长和头胸甲长（0．86）之间的遗传相关,以体长和头胸甲长之间的遗传相关最小（0．83）。[结论]中国对虾体长、头胸甲长、腹节长和体重性状表型相关在0．80一O．90,t检验均达到极显著水平（P〈0．01）。     

樟树一年生幼苗遗传变异研究

对引种在福建省连城县姑田镇的樟树幼苗进行调查,结果表明,引种的24个家系生长良好,仅部分家系生长低于对照家系。方差分析的结果表明群体间生长差异显著。除苗高遗传力（0.52）以外,地径与材积的遗传力均为0.38,说明苗高受较强的遗传控制,而地径和材积受较弱的遗传控制。遗传变异系数与变幅说明群体个体间生长差异显著。通过对引种的24个家系进行聚类分析,可分为3类,速生家系为7个,多为广东的家系。中等家系和生长较差的家系中多以福建和江苏省的家系为主。     

Genetic and phenotypic parameter estimates for growth traits in Boer goat

An understanding of influencing factors and genetic principles affecting the growth traits is needed to implement optimal breeding and selection programs. In this study, heritabilities (direct additive and maternal) of body weights at birth (BW0), 90 days (BW90) and 300 days (BW300) of age and average daily gains from birth to 90 days (ADG0-90), birth to 300 days (ADG0-300) and 90 days to 300 days (ADG90–300) of age in Boer goats were estimated on the basis of 1520 Boer goats at Boer Goat Breeding Station in Yidu, China, during 2002–2007. The parameters were estimated using a DFREML procedure by excluding or including maternal genetic or permanent maternal environmental effects, four analysis models were fitted in order to optimize the model for each trait. Influencing factors such as parity, litter size, kidding year and season, as well as sex of kids and some significant interactions among these factors were investigated as the fixed effects for the models. The results showed that the birth year and maternal genetic effects such as parity and litter size of dam were important determinants of the genetic parameter estimates for pre-weaning growth traits, and environmental effects such as birth year, season and sex of kids had some significant effect on post-weaning growth traits. The mean values and standard errors (SE) of direct additive heritability estimates calculated with the optimum model were 0.17 ± 0.07, 0.22 ± 0.08, 0.07 ± 0.07, 0.10 ± 0.08, 0.30 ± 0.12 and 0.08 ± 0.10 for BW0, BW90, ADG0-90, BW300, ADG0-300 and ADG90–300, respectively. For pre-weaning weights, correlation estimates between direct additive and maternal genetic (r_a–m) effect were high and negative ranging from − 0.74 to − 0.86.     

油菜主要农艺性状的配合力及杂种优势分析

用6个细胞质雄性不育系与5个恢复系配置30个杂交组合(6×5)。对这30个杂交组合及其亲本6个同型保持系、5个恢复系的16个农艺性状进行了2 a重复鉴定,发现不同性状及同一性状不同年份间,配合力表现不尽一致,综合2 a结果,父本的优劣顺序为L161>Q3>Q1>Yuyou 1>227,母本为L89>L451>L656>Zhong 2>D89>1500100285。不同性状及同一性状不同年份间,遗传力存在差异,以初花期、单株产量、主花序长度和单株角果数的遗传力比较稳定,幼苗重、主花序角果数和千粒重的遗传力变化较大。除抽薹期和开花期的超中亲优势不显著外,其他14个性状均存在一定程度的正向优势,单株种子产量和小区产量的超亲优势值最高,其次为幼苗重、分枝高度、角果数。参试组合中,有2个组合(L89×Yuyou 1、L451×Q3)的小区产量表现出较明显的超标优势(5.44%、4.87%)。种子产量的3个主要构成性状(角果数、角粒数和千粒重)中,角果数的杂种优势最大,说明单株角果数的优势是引起小区产量优势的主要原因。最后还对捷克等欧洲优质油菜的利用策略进行了讨论。     

Analysis of starch swelling power in Australian breeding lines of hexaploid wheat (Triticum aestivum L.)

Starch is the major component of wheat (Triticum aestivum L.) grain and is composed of two large glucan molecules, amylose and amylopectin. The ratio between the two polymers types influences the water absorbing properties of starch upon heating, and thus affects the end-use of grain and purified starch. In this study, we evaluated the starch swelling power (SSP) values in seven wheat populations developed from crosses involving low-SSP lines. Analysis of starch produced by the F₂ generation plants showed that the largest SSP variation (11.4–16.2) and lowest SSP mean (13.9) was obtained for a population derived from doubled haploid lines SM1028 (SSP = 14.5) and VK306 (SSP = 13.6). The population of 360 lines was advanced by single seed descent to the following generations for further studies. Starch analysis of grain produced by F₄ generation lines in two field locations during 2006 and in a greenhouse environment during 2005 showed that SSP values were relatively stably inherited. The average broad-sense heritability was 73% and significant (P < 0.001) genotype × genotype and genotype × environment interactions were seen. Starches with the highest and lowest SSP values were inversely related to amylose concentration determined by high pressure liquid chromatography (HPLC)–size exclusion chromatography (SEC) of debranched starch. Developed lines with the lowest SSP values surpassed 40% in apparent amylose concentration. The study illustrates that screening for SSP in early generations can be used to develop wheat lines with desired starch swelling characteristics.     

大豆杂种第二代种子蛋白质、脂肪及其组份的配合力与遗传力分析

以 NCD-Ⅱ设计固定模型研究了3个东北大豆品种、5个美国品种(系)的 F_2代种子蛋白质、脂肪及其组份的配合力和遗传力。1.3个东北品种在产量、单株粒重、蛋白质、脂肪、蛋氨酸、亚麻酸含量、蛋白质总量、脂肪总量等11个性状上 gca 差异显著;5个美国品种(系)在蛋白质、油酸、亚麻酸含量等5个性状上有显著的 gca变异。各性状的加     

杉木种子园中无性系间结实和种子品质差异研究

在观察的31个无性系中丰产的约占20％,产量约占总产30％;中等的占60％弱,产量占54％;低产的占20％强,产量约占17％。结实的广义遗传力hw~2平均0.66。不同无性系在雌雄花比、雌花序结构、球果大小和分枝稠密度等方面存在差异。一般植株“偏雌性”、聚生雌花序占优势,球果大、树冠表面积大而分枝稠密的无性系结实量高;反之,“偏雄性”、单生雌花序为主、球果小、树冠表面积小而分枝稀疏的无性系结实量低。据72个无性系的分析,大粒种子无性系约占21％,中粒的约占47％,小粒的占32％;高发芽率无性系占23.6％,中发芽率的占57％,低发芽率的占19.4％。大粒种子无性系的发芽卒往往高于中、小粒种子无性系;而发芽势有相反趋势。     

小麦穗发芽敏感性的配合力分析

为了探讨冬小麦穗发芽敏感性的遗传特点，并为小麦的抗穗发芽育种提供科学依据，对穗发芽敏感性不同的4个红皮和3个白皮小麦品种进行完全双列杂交，并对杂交材料进行配合力分析。结果表明，小麦收获前穗发芽性受加性效应、非加性效应和细胞质效应的共同影响，说明小麦的穗发芽抗性能够稳定地遗传给后代；小麦穗发芽敏感性的广义遗传力和狭义遗传力都比较高，说明小麦的穗发芽性主要受遗传因素决定。所以在穗发芽抗性育种中，早代选择是有效的。