彩色棉的研究与产业化

彩色棉是一种纤维中含有色素类物质的特殊类型的棉花，原始种多来自美洲大陆和中美洲的短纤维野生彩色棉，栽培的彩色棉大多是利用与白色棉进行杂交选育而成的。用彩色棉加工成的纺织品无需漂白、印染、消毒等传统工艺处理，不产生化学污染，衣物中不含有害成分与任何化学物质残留，是典型的环保健康产品，备受消费者的欢迎。本文简述了国内外在彩色棉遗传特性、品种选育等方面的研究以及产业化的动态，分析了彩色棉生产中存在的问题并提出了相应的解决方案。     

Influence of food quality and quantity on the growth and development of Crassostrea gigas larvae: a modeling approach

A biochemically based model was developed to simulate the growth, development and metamorphosis of larvae of the Pacific oyster, Crassostrea gigas. The model is unique in that it (1) defines larvae in terms of their protein, neutral lipid, polar lipid, carbohydrate and ash content; (2) tracks weight separately from length to follow larval condition index and (3) includes genetic variation in growth efficiency and egg quality to better simulate cohort population dynamics. The model includes parameterizations for larval filtration, ingestion and respiration that determine growth rate and processes controlling larval mortality and metamorphosis. Changes in tissue composition occur as the larva grows and in response to the biochemical composition of the food.

The simulations show that genetically determined variations in growth efficiency produce significant changes in larval survival and success at metamorphosis. Larvae with low growth efficiency are successful under a much narrower range of culture conditions than larvae with high growth efficiency. The impact of low growth efficiency is primarily controlled by the ability of larvae to store lipid for metamorphosis. Culture conditions that provide increased dietary lipid counterweigh low growth efficiency. Changes in food quantity and quality had little effect on size at metamorphosis. On the other hand, larval life span and success rate at metamorphosis varied over a wide range depending upon the conditions of the simulation. Food quality and food availability both influence larval life span and, hence, larval survival. As ingestion rate decreases, larval life span increases and cohort survival declines. Increased lipid or decreased protein in the diet improves cohort survival. Changes in carbohydrate content are less influential. If cohort success is significantly affected by mortality during larval life rather than success at metamorphosis, the influence of food quality becomes more complex. The range of food compositions yielding high survival is restricted by a balance between improved success at metamorphosis obtained by increased lipid storage and the shortening of larval life span as a result of more rapid growth, a function of protein availability. These simulations illustrate the strength and utility of numerical models for evaluating and designing hatchery protocols for optimizing yield of C. gigas larvae.     

水稻粒重的粒位效应及遗传分析

选用6个粒重差异较大的粳稻亲本,按完全双列杂交方式配制30个杂种F1、2个F2及部分回交组合,研究了同一稻穗不同粒位粒重的变异度和籽粒谷粒性状的遗传,结果表明:上部籽粒粒重的变异度极显著地小于中、下部;不同粒位粒重的变异度随着粒重的增高而增大,这一特征在下部小穗表现明显,而上、中部小穗,粒重在30g以下时,粒重的变异度没有显著差异。不同粒位的小穗结实率存在极显著差异,上、中部明显高于下部。粒重相关性状具有较高的遗传力,环境对这些性状的影响很小,表明粒重的变异主要受遗传控制。在遗传作用中,基因的加性作用是主要的,因而谷粒性状可以在早代进行选择。杂交后代群体随着世代增加、基因纯合度提高,其平均粒重有下降的趋势。     

DNA Testing in Neurologic Diseases

DNA testing is available for a growing number of hereditary diseases in neurology and other specialties. In addition to guiding breeding decisions, DNA tests are important tools in the diagnosis of diseases, particularly in conditions for which clinical signs are relatively nonspecific. DNA testing also can provide valuable insight into the risk of hereditary disease when decisions about treating comorbidities are being made. Advances in technology and bioinformatics will make broad screening for potential disease‐causing mutations available soon. As DNA tests come into more common use, it is critical that clinicians understand the proper application and interpretation of these test results.     

水稻品种抗褐稻虱的遗传机制及表型稳定性的研究

本文研究了15个水稻品种的抗性遗传，品种国眉占的抗性受一对隐性基因控制，BG367－4受两对隐性基因控制；三桂占1、Suweon294、KAU1727、IR13539－100－2－2－2－3、IR749－5－2－1－1以及IR13240－108－2－2－3均受一对显性基因控制；IR25586－108－1－2－2－2受两对显性基因控制；三黄占2、三叶占1、铁六选；新惠占1、GENG77－4以及IR13427－40－2－3－3都受一对显性基因和一对隐性基因因控制，同时对12个具有不同抗性水平的水稻品种苗期的抗菌表现进行了遗传型稳定性分析。结果表明，不同品种的抗性稳定性有明显差异，TN1是极稳定的高感品种TG367－4、25586-108－1－2－2－2以及Mudgo是非常稳定的高抗;一叶占1、三桂占1和铁六这三个抗级品种的抗虫也较稳定;；而抗级品种国眉占、三黄占2、Suweon294和抗品种包选2、辐包矫21的抗虫性不稳定。     

Tomato early blight (Alternaria solani): the pathogen, genetics, and breeding for resistance

Alternaria solani causes diseases on foliage (early blight), basal stems of seedlings (collar rot), stems of adult plants (stem lesions), and fruits (fruit rot) of tomato. Early blight is the most destructive of these diseases and hence receives considerable attention in breeding. For over 60 years, breeding for early blight resistance has been practiced, but the development of cultivars with high levels of resistance has been hampered by the lack of sources of strong resistance in the cultivated tomato and by the quantitative expression and polygenic inheritance of the resistance. In some accessions of wild species, high levels of early blight resistance have been found, but breeding lines still have unfavorable horticultural traits from the donor parent. Recently, the first linkage maps with loci controlling early blight resistance have been developed based on interspecific crosses. These maps may facilitate marker-assisted selection. This overview presents the current knowledge about the A. solani–tomato complex with respect to its biology, genetics, and breeding.     

玉米抗倒性的遗传研究进展

倒伏严重影响玉米产量而且还影响玉米的机械化收获,是当前玉米生产和育种中一个主要问题。玉米的抗倒性受到植株受力因素与植株支持系统两方面的影响。讨论提高玉米抗倒性的遗传因素以及综述与其相关的遗传机制研究进展。     

转甘蔗pepc基因籼稻恢复系N175的遗传学分析

磷酸烯醇式丙酮酸羧化酶(PEPCase)是C4双羧酸循环途径中CO2固定初始反应的一种酶,在该酶作用下,C4植物的光合速率,特别是在强光高温条件下,明显高于C3植物.甘蔗属于禾本科甘蔗属,为C4作物之一.本研究对转甘蔗pepc基因水稻恢复系N175的转基因后代进行遗传学分析,Southern blot检测结果表明,甘蔗pepc基因已经整合到水稻恢复系N175基因组中,在一些转基因株系中,甘蔗pepc基因以单拷贝的方式整合到杂交水稻恢复系N175的基因组中.对转甘蔗pepc基因的水稻恢复系N175株系进行光合效率分析,结果表明转基因株系的光合效率显著高于非转基因对照.在转基因株系中,最高的光合效率为26.50μmol·m-2·s-1,与非转基因对照相比,光合效率提高了106%,说明甘蔗的pepc基因在一定程度上可以提高转基因水稻的光合效率.     

应用极大似然法分析小麦穗长的遗传

采用质量—数量性状遗传的极大似然分析方法,对长穗小麦品系93(220)的主茎穗长进行了质量—数量遗传模型测验和主、微基因效应与变异估计。结果表明:长穗小麦新品系93(220)的主茎穗长为一典型的质量—数量性状,由一个主基因和若干微基因共同控制;一对隐性主基因控制穗长,附合加性——显性遗传模型,F1代表现为部分显性,隐性主基因增加主茎穗长的效应平均为1.47,微基因遗传效应为2.83cm,隐性主基因个体主茎穗长表现为长穗。     

基于遗传学实验教学改革的大学生科研素质培养探索

遗传学实验是遗传学课程教学的必要组成部分.该研究从改变传统遗传学实验的单一教学目标出发,对实验内容进行拓展、延伸,并通过实验、实践的实例激发大学生学习遗传学知识的兴趣和动力;以及通过查阅、探讨本领域最新国际研究进展,捕捉大学生在实验项目基础上迸发出来的科学微火花,积极获取高校各类大学生科研项目的资助等方面进行探究,旨在通过该类教学改革逐渐培养大学生的基本科研素质.