355份粳稻种质资源在新疆的遗传多样性分析及综合评价

为筛选出适合新疆种植的综合性状较优的水稻种质资源,对国、内外355份水稻资源的17个质量性状和20个数量性状进行综合评价。结果表明：在质量性状指标中穗抽出度、二次枝梗、穗立形态、叶片茸毛和分蘖力上表现出丰富的变异类型;数量性状变异范围为3.906%～57.519%,遗传多样性指数为1.713～2.067。通过对数量性状进行聚类分析将355份水稻种质资源划分为4大类群,类群Ⅰ属于极端粒型的特异性种质,共97份;类群Ⅱ属于潜在增产种质,共81份;类群Ⅲ属于晚熟极端种质,共94份;类群Ⅳ属于优质高产种质,共83份。20个数量性状利用主成分分析提取5个综合因子,累计贡献率为74.989%,各成分的贡献率分别为17.472%(PC1)、17.071%(PC2)、15.738%(PC3)、15.237%(PC4)和9.429%(PC5);水稻种质资源的综合得分范围为0.416 8～1.240 8,综合得分前10名的种质资源依次为‘21Y137’‘21Y271’‘21Y162’‘21Y280’‘21Y276’‘21Y87’‘21Y132’‘21Y254’‘21Y294’‘21Y318’,均属于类群Ⅳ...     

DNA分子标记在甘薯遗传育种中的应用

DNA分子标记是继形态标记、细胞标记和生化标记之后发展起来的一种新的较为理想的遗传标记,在甘薯育种方面发挥了重要作用。主要概述了分子标记在甘薯的起源、进化与分类、图谱构建、遗传多样性分析、品种鉴定、基因定位与辅助育种等方面的研究进展,并对甘薯的分子育种提出了展望。     

基因工程对改良观赏植物品质的研究进展

基因工程技术已在观赏植物的花色、花形、花香、花期、抗性等方面大量应用并取得了较大的进展,为花卉的性状和品质改良提供了全新的思路和手段。作者就近年来基因工程技术在观赏植物品质研究方面进行了综述,并对观赏植物基因工程存在的问题进行了探讨。     

美洲黑杨新无性系生根性状的遗传分析

对12个美洲黑杨无性系生根性状遗传变异的研究表明,不同无性系在最早生根时间、主根总数及主根总长等方面均存在极显著差异。水培不同时期主根总数、主根总长的广义遗传力在0.657 0~0.691 1、0.617 5~0.785 9之间,表明这两个生根性状在无性系间具有稳定的遗传变异,且受中等至强度遗传控制,具有较大的选择潜力。采用50~150 mg/L ABT溶液预处理对各无性系诱导根平均根数和平均长度有不同程度的促进作用,且以50 mg/L ABT溶液预处理后长势最好。     

两系杂交水稻糙米率的配合力研究

选用8个籼型光温敏不育系作母本,30个恢复系品种作父本,共配制两系杂交水稻组合74个,进行两系杂交水稻糙米率配合力遗传研究.结果表明:1)两系法杂交水稻杂种F1谷粒的糙米率与父本(恢复系)和双亲平均的谷粒糙米率呈极显著正相关,相关系数为0.3123和0.3068;与母本(不育系)谷粒糙米率相关不显著,相关系数为0.1031.2)6×6不完全双列杂交法配合力分析结果表明,两系杂交水稻糙米率性状的表现在组合间差异极显著;父、母本的一般配合力效应和组合的特殊配合力效应差异显著;父、母本的一般配合力作用大于组合的特殊配合力作用,一般配合力方差占总个基因型方差的65.02%,特殊配合力方差占34.98%;一般配合力作用,父本的作用(基因型方差为63.70)大于母本的作用(基因型方差为55.34).     

大红甜橙遗传转化高效再生体系的建立

以大红甜橙的实生苗为试材,研究6-BA与IAA的不同浓度组合和Km不同浓度对大红甜橙不同外植体离体再生的影响和IBA的不同浓度对不定芽生根的影响,建立了高效的大红甜橙遗传转化再生体系.该体系的最佳条件是:1)以实生苗上胚轴为外植体.2)以MS无机盐 100mg/L肌醇 0.2mg/LV-B1 1mg/LV-B6 1mg/L烟酸 3%蔗糖 0.8%琼脂(pH5.8) 3mg/L6-BA为不定芽诱导培养基,在26℃黑暗条件下培养7d后,转移至光/暗周期16/8h的条件下诱导不定芽的分化(40d分化率达90%).以1/2MS 3%蔗糖 0.7%琼脂 2.0mg/LIBA为不定芽的生根培养基(40d生根率达94.7%).3)筛选遗传转化转化体的Km质量浓度为50mg/L.     

Multilocus sequence typing detects new Piscirickettsia salmonis hybrid genogroup in Chilean fish farms: Evidence for genetic diversity and population structure

Piscirickettsia salmonisis the causative bacterial pathogen of piscirickettsiosis, a salmonid disease that causes notable mortalities in the worldwide aquaculture industry. Published research describes the phenotypic traits, virulence factors, pathogenicity and antibiotic‐resistance potential for various P. salmonisstrains. However, evolutionary and genetic information is scarce for P. salmonis. The present study used multilocus sequence typing (MLST) to gain insight into the population structure and evolution of P. salmonis. Forty‐two Chilean P. salmonisisolates, as well as the type strain LF‐89^T, were recovered from diseased Salmo salar, Oncorhynchus kisutchand Oncorhynchus mykissfrom two Chilean Regions. MLST assessed the loci sequences of dnaK, efp, fumC, glyA, murG, rpoD and trpB. Bioinformatics analyses established the genetic diversity among P. salmonis isolates (H = 0.5810). A total of 23 sequence types (ST) were identified, 53.48% of which were represented by ST1, ST5 and ST2. Population structure analysis through polymorphism patterns showed few polymorphic sites (218 nucleotides from 4,010 bp), while dN/dS ratio analysis indicated purifying selection for dnaK, epf, fumC, murG, and rpoD but neutral selection for the trpB loci. The standardized index of association indicated strong linkage disequilibrium, suggesting clonal population structure. However, recombination events were detected in a group of seven isolates. Findings included genogroups homologous to the LF‐89^T and EM‐90 strains, as well as a seven‐isolate hybrid genogroup recovered from both assessed regions (three O. mykiss and four S. salar isolates). The presented MLST scheme has comparative potential, with promising applications in studying distinct P. salmonis isolates (e.g., from different hosts, farms, geographical areas) and in understanding the epidemiology of this pathogen.     

Genetic parameters for spawning and growth traits in the Pacific white shrimp (Penaeus (Litopenaeus) vannamei)

The aim of this study was to estimate genetic parameters for spawning traits and growth traits in a breeding line of Pacific white shrimp, Penaeus (Litopenaeus) vannamei, selected for growth and survival. Traits studied were number of eggs (NE) and number of nauplii (NN) and female body weight at insemination (FWI) and body weight at 130 days of age (BW130). Genetic parameters were estimated using a multivariate animal model. Heritability for NE and NN were estimated as 0.13 ± 0.04 and 0.03 ± 0.04 respectively. The contribution to NN total variation due to ‘factors associated with male’ effect was estimated as 0.47 ± 0.07. In the cases of FWI and BW130, heritability was estimated as 0.44 ± 0.08 and 0.19 ± 0.03 respectively. Genetic correlation between FWI and NE was estimated as 0.49 ± 0.15, between FWI and NN as 0.54 ± 0.39 and between NE and NN as 0.27 ± 0.41, whereas the genetic correlations of FWI, NE and NN with BW130 were 0.30 ± 0.13, ?0.21 ± 0.19 and ?0.25 ± 0.38 respectively. Although it is important to perform more studies on this issue, our results found no evidence of a genetic antagonistic effect between female reproductive traits and body weight at harvesting (130 days of age) in P. vannamei.     

主要养殖鲑科鱼类遗传育种的研究进展

冷水性鲑科鱼类肉质鲜美,高蛋白、高不饱和脂肪酸、营养丰富、无肌间刺、易加工,是世界性养殖鱼类,其中大西洋鲑、虹鳟和红点鲑属鱼类等主要养殖鲑科鱼类,一直是水产遗传育种领域的重要研究对象。本文简要叙述了鲑科鱼类遗传育种研究的历史和现状,主要介绍了经济性状遗传参数估计、选择育种、分子遗传与标记辅助育种等方面的研究进展,提出了我国鲑科鱼类遗传育种工作重点研究的方向。     

条斑紫菜6个品系的SRAP分析

为鉴别条斑紫菜不同品系的种质,使用相关序列扩增多态性(sequence-related amplified polymorphism,SRAP)标记对条斑紫菜的5个选育品系和1个野生品系进行遗传分析,结果从35对引物组合中筛选出可扩增出稳定清晰条带的组合11对,共获得131个扩增位点,其中多态性位点125个,多态性比例高达95.42%。6个品系 间的遗传距离为0.364 3～0.867 9,平均为0.593 0。用UPGMA法进行聚类分析,结果将6个品系分为2个群,所反映的亲缘关系与各品系的来源基本一致,说明SRAP 标记技术可以成为条斑紫菜品系间遗传分析的有效工具。在131个多态性位点中,选择扩增出的4个位点构建了6个品系的指纹图谱。另外,通过ME1/EM6引物组合 扩增得到耐高温品系TM-18的特异性条带,经回收测序和重新设计引物,该条带在其丝状体和叶状体DNA中均能稳定地被扩增出来,可用于该品系的种质鉴别 。