棉蚜茧蜂对不同品种、不同生育期棉花的趋性行为反应

【目的】研究棉蚜茧蜂对不同品种、不同生育期棉花的趋性行为反应,为了解天敌昆虫与寄主之间关系,利用棉蚜茧蜂对棉蚜等害虫进行防控。【方法】以生产上大面积种植的GK-12(对照为泗棉3号)、新棉33B(亲本为新棉33)和SGK321(亲本为石远321)等3组棉花品种为材料,于棉花7叶期、现蕾前期和现蕾期,设计无虫棉植株、被棉蚜为害后剔除虫体的植株以及棉蚜+有虫株等3种不同处理,借助“Y”型嗅觉仪,检测棉蚜茧蜂在棉花不同生育期对这3种不同处理的趋性。【结果】棉蚜茧蜂无法识别健康的常规棉和转基因棉花植株;对不含棉蚜的被害棉来说,转基因棉对棉蚜茧蜂更具吸引力。而对含有棉蚜的有害棉来说,除7叶期GK12、新棉33B和现蕾期GK12这3组处理外,其他各组的转基因棉对棉蚜茧蜂均具较强的吸引作用。【结论】两类不同的棉花品种对棉蚜茧蜂不存在排斥性,棉蚜为害转基因棉花后更能吸引棉蚜茧蜂。     

杉木第2代种子园效果分析

调查分析了广东龙山林场杉木第2代种子园母树生长、结实情况和种子播种品质及2代园子代测定与现实增益等．结果显示：嫁接6～8年,2代园母树保存率74．39％,正冠率87．65％,母树生长正常．结实株率50．45％,单株结实指数1．52,母树结实力中下。球果出籽率、种子千粒质量、发芽率和发芽势分别为3．24％、6．554g、31．74％和23．16％,种子播种品质总体上优于同龄初级种子园,但劣于1．5代种子园．来自广东、广西的建园亲本,在结实力及子代速生性方面均优于来自福建、贵州、湖南的亲本．4年生子代测定结果表明,2代园材积现实增益7．58％～10．60％,建设2代园提高种子遗传品质的关键目的已实现,广东龙山2代种子园营建基本上是成功的。     

Effects of different angling practices on post-release behaviour of nest-guarding male black bass, Micropterus spp.

Abstract  This study evaluated how different angling practices affect the short-term post-release behaviour of nest-guarding male black bass, Micropterus spp. Male largemouth bass, M. salmoides (Lacepède), and smallmouth bass, M. dolomieu (Lacepède), were angled from their nests and subjected to treatments designed to simulate a variety of common angling practices associated with catch-and-release angling, including fishing tournaments. In addition, some nests had broods reduced (removal of the majority of the eggs or fry from the nest) during the angling treatments to simulate predation of offspring during the angling event. Fish subjected to procedures simulating fishing tournaments (including a 1-h livewell confinement and release 100 m from the nest) exhibited significantly longer rest periods prior to returning to their nest than did other treatment groups. This rest period was longer for largemouth bass than smallmouth bass. Brood removal and air exposure increased abandonment rates compared with controls. These results show that sublethal stressors inherent in some angling practices (such as air exposure and livewell confinement) may delay the return of male black bass to their nest. In the presence of nest predators, the delay in return time could result in increased nest abandonment.     

杉木第二代种子园亲本性状遗传变异研究

以沙县官庄国有林场22年生的杉木第2代种子园为研究对象,对220个无性系进行系统测定,探讨了无性系生长、形质和结实性状的遗传变异规律,结果表明:生长性状、形质性状和结实性状在无性系间的差异达到极显著水平,而且无性系的重复力值均较大;从220个无性系中综合筛选出丁74等35个优良无性系,各优良无性系生长量大、结实性状良好,22年生时的平均树高、胸径、材积值分别高达17.56 m、33.60 cm和0.803 35 m3,分别大于种子园中调查的220个无性系平均值的20.36%、17.73%和57.32%,综合性状表现优良,可用作高世代种子园建园材料和杂交育种的亲本材料。     

ISSR分子标记对杧果实生苗父本的早期鉴定

[目的]采用ISSR分子标记技术对杧果实生苗进行亲本早期鉴定,为提高杧果育种效率提供参考.[方法]采用ISSR分子标记技术,筛选不同引物鉴定97-1实生苗的父本.[结果]采用优化的ISSR反应体系,从18条引物中筛选获得4条特异引物UBC-848、UBC-857、UBC-864和UBC-868,其扩增条带多、稳定性强、多态性高、背景清晰.利用引物UBC-848、UBC-857、UBC-864、UBC-868分别对四川红柁、紫花柁和97-1实生苗进行扩增,获得的扩增片段长度在100～2000bp,四川红杧与97-1实生苗、紫花杧与97-1实生苗的共有特异性条带约为180和380 bp、280和380 bp、180和680 bp、680和770bp.[结论]采用ISSR分子标记技术和引物UBC-848、UBC-857、UBC-864、UBC-868构建了杧果实生苗亲本鉴定体系,可鉴定出97-1实生苗的父本为四川红杧,97-1实生苗是紫花杧和四川红杧的杂交种.     

When and why do smallmouth bass abandon their broods? The effects of brood and parental characteristics

Abstract Variation in brood abandonment was explored by conducting partial brood removals from smallmouth bass, Micropterus dolomieu Lacepède, nests in two north temperate lakes. In both lakes, percent of the brood removed had no effect on nest failure rates. Nest failure prior to offspring swim‐up was more common, but unrelated to brood size after removal, in the lake with higher post‐spawning mortality and lower growth and fecundity. Brood size after removal was negatively related to nest failure in the lake with high survival, growth and fecundity. Nests guarded by young males failed more frequently than those of old males, and young broods failed more frequently than old broods. Dynamic programming and logistic regression models developed to predict nest fate worked better for the lake with selective pressures that theoretically favoured abandonment (e.g. high post‐spawning mortality). Both models identified male age and brood age as important factors in predicting nest fates. Because nest success is related to the age of the parent, this could have consequences for overall nest success for populations with different demographics.     

Detection of repeated genotypes among 93 diploid wheat accessions

Summary An objective procedure was developed to find and eliminate repeated genotypes from a set of crop cultivars or accessions which may be used as parents for future plant breeding programs. Nonhierarchical, nonexclusive, exhaustive cluster analysis was used to group 93 diploid wheat accessions using LSD multiple comparisons of accession means based on data measured on seven characters. Beginning with the rarest accessions, i.e. those represented in the fewest clusters resulting from the clusters analysis, a minimum number of the accessions were chosen to represent the phenotypes of all 93 of the accessions. Two analyses were performed, one using data from an irrigated trial, the other from a dryland trial. The dryland trial data was more discriminating in that it required 71 accessions to represent all of the clusters generated from the original 93 accessions while the irrigated trial data required only 60 of the 93 accessions. In addition to the 71 accessions chosen from the dryland trial analysis, the irrigated trial analysis suggested an additional 12 accessions were phenotypically and, therefore, genotypically unique. The total of 83 unique accessions left 10 phenotypically duplicate accessions to be eliminated from the set of potential parents. Four of the 10 duplicated accessions were rare in that they were represented in very few clusters in either the irrigated trial analysis or in the dryland trial analysis. Because their phenotypes were not unique in spite of being rare, we believe such accessions were duplicated genotypically as well as phenotypically. The other six duplicates were common in that they were represented in a large number of clusters. Such accessions may not prove to be duplicates if grown in additional environments (trials), or if measured on additional characters.     

Callipyge基因概述

综述了引起绵羊表现双肌臀性状的Callipyge基因对绵羊胴体品质及化学成分等的影响，并着重对Callipyge基因的特殊遗传现象进行了解释．     

杂交水稻三系亲本新,陈种子生育特性研究

对目前生产应用的２０个三系亲本新、陈种子生育期等性状进行研究。结果表明，晚季种植新种子比陈种子生育期延长，叶片数增加；早季种植除个别亲本外，新、陈种子生育期基本相同；不同亲本间新、陈种子生育期变化差异甚大。     

Parental Selection in Rice Cultivar Improvement

The evaluation of rice (Oryza sativa L.) cultivars assists breeders in identifying useful trait relationships and in selecting parents as donors of specific traits. This study was conducted to compare long-grain rice cultivars using genotype × trait (GT) biplot analysis and determine potential donors of traits related to grain yield and quality. Seventeen cultivars in the 2005 and 2006 Uniform Regional Rice Nursery in Beaumont, Texas, USA were analyzed for 20 traits using GT biplot analysis. The GT biplots showed the diversity among cultivars with regards to yield-related traits. Cultivars recommended as donor parents were: Trenasse, Spring, Presidio, and Cocodrie for high grain yield and head rice rate; Trenasse and Presidio for semi-dwarfness; Banks for tall plant height; Wells for high flag leaf area, panicle weight, and number and mass of filled grains per panicle; Hidalgo for high tiller density; Francis for high number of spikelets per panicle; Spring and Trenasse for short flowering duration; Cheniere for more days to heading and maturity and Spring for less days; and Spring and Hidalgo for high grain weight. Breeders can use these cultivars with specific traits to increase grain yield and quality.