陆地棉枯萎病抗性的遗传研究

本研究采用最小范数二阶无偏估算法[MINQUE(1 ) ]的统计方法 ,分析加性—显性—母体 (ADM)遗传模型、加性—显性—上位性(ADAA)遗传模型 ,估算陆地棉 8个杂交亲本和F1、F2 代各 2 8个组合的枯萎病抗性遗传效应。结果表明 ,陆地棉枯萎病抗性的遗传无上位性效应 ,有不显著母体效应存在 ,因而采用 ADM模型分析 ,加性方差为 2 8.0 8,显性方差为 7.35,母体方差是 0 .43,分别占表现型方差的 49.9%、1 3.1 %、0 .8% ;广义遗传率为 63.0 % ,狭义遗传率为49.9%。陆地棉枯萎病抗性的遗传主要是加性效应和显性效应 ,以加性效应为主     

硅及其吸收基因Lsi1调节水稻耐UV-B辐射的作用

硅能提高植物对生物和非生物胁迫的抗性,水稻是吸收硅较多的作物之一。本研究以UV-B耐性水稻Lemont和UV-B敏感水稻Dular及其硅吸收基因(Lsi1)的转基因水稻为材料,研究硅与水稻耐UV-B辐射的关系。结果发现,自然光照条件下,缺硅培养的UV-B耐性水稻Lemont和UV-B敏感水稻Dular叶片的苯丙氨酸解氨酶(Phenylalanine ammonia lyase, PAL)和光裂解酶(Photolyase, PL)基因的表达以及总酚、类黄酮的含量都分别低于加硅的处理; UV-B辐射后,上述指标在不同硅处理的两水稻中都增加和增强,但缺硅培养的水稻仍显著低于加硅培养的水稻。进一步分别以Lsi1被抑制、增强的两种转基因Lemont水稻,以及Lsi1增强的转基因Dular水稻为材料,采用加硅培养的方式对转基因水稻的上述指标进行研究,结果也发现,抑制水稻Lsi1基因表达,其叶片PAL、PL基因表达也下调,总酚、类黄酮含量降低,此结果与缺硅培养下的野生型植株相似; 增强表达Lsi1基因则结果相反。UV-B辐射后,上述指标也增强和增加,但在相同的水稻品种中仍表现为Lsi1被抑制的植株最低,Lsi1增强的植株最高。研究结果表明,通过调节水稻Lsi1能够改变水稻耐UV-B辐射的能力。     

烟草青枯病抗性的遗传分析

为了解烟草青枯病抗性的遗传方式,为制定抗性育种方案提供依据,选用15份对烟草青枯病抗性程度不同的烟草种质,应用完全双列杂交方法配制组合,于2010年、2011年进行烟草青枯病病圃抗性鉴定,利用相关软件分析青枯病抗性的遗传效应。结果表明：烟草青枯病抗性以加性效应为主,显性效应不明显,存在加性×加性上位性;加性及其上位性与环境有互作效应;抗性狭义遗传力在30.40%~57.14%之间。     

小麦抗源材料0911-3抗白粉病的主基因+多基因遗传分析

为了解小麦抗源材料0911-3对白粉病的抗性遗传规律,以0911-3为母本与极度感病品系1130-2杂交,产生P1、P2、F1、BC1、BC2和F2共6个家系世代,分别以倒二叶病害严重度(MDS)和病程曲线下叶面积(AUDPC)为成株抗性指标,应用主基因+多基因混合遗传模型多世代联合分析方法进行遗传分析.结果表明,0911-3对白粉病的2种成株抗性指标的遗传基础基本是一致的,都符合2对加性-显性-上位性主基因+加性-显性-上位性多基因遗传模型;2对主基因都具有负向加性效应,可以增强抗病性,显性效应为正向,感病基因具有部分显性作用;2对主基因间还存在各种相互作用,可以增强抗病性;分离世代以F2主基因+多基因遗传率为最高,MDS和AUDPC的遗传率分别为91.87％和92.22％.     

陆地棉黄萎病抗性的遗传分析

本研究采用MINQUE(1)的统计方法,用ADM模型、ADAA模型、AD模型［1］,估算陆地棉8个杂交亲本和F1、F2代各28个组合的黄萎病抗性遗传效应。结果表明,陆地棉黄萎病抗性的遗传不存在母体效应和上位性效应,因而采用AD模型分析,加性效应占52.43,显性效应为9.01,均达极显著水平;广义遗传率为83.04%,狭义遗传率为70.87%。     

陆地棉主要经济性状的遗传分析

通过陆地棉主要经济性状的基因效应方差分析,表明产量性状显性方差占表现型变异比率最高,单株铃数显性×环境方差占62．4％,达极显著水平。纤维品质性状中,2．5％跨长、比强度及麦克隆值分别以显性方差、加性方差和加×加上位性方差为主。产量性状普通狭义遗传率、普通广义遗传率最高的均是衣分,最低的都是单株铃数。互作狭义遗传率最高的也是衣分,为11．4％,单株铃数和单铃重互作广义遗传率较高,都在68％以上。2．5％跨长的普通狭义遗传率最低,仅为4．2％,比强度普通狭义遗传率高达55．5％。同时还计算了各对性状基因型相关值。     

小麦赤霉病抗性与农艺性状的相关性分析

该研究采用我省6个小麦主栽品种与9个优良亲本按6×9不完全双列杂交配制54个组合,分别对杂种F_1和亲本的5个产量性状和3个抗性指标进行多种遗传相关分析。结果表明:1、株高与抗性指标的遗传、加性、和表型相关系数在-0.585～-0.885之间,均达到显著和极显著水准,并在遗传相关中以加性成分为主。2、单株产量性状与抗性指标大多呈负向加性、显性、遗传、和表型相关。但几乎都不显著,即抗性和产量并不矛盾。3、病粒率与病情指数的遗传、表型相关,以及遗传相关中的加性、显性相关均呈极显著正相关,但两者与病穗率这一指标的遗传相关未能达到显著水平。小麦抗赤霉病的性状鉴定以前两项较合理,病穗率仅为参考指标,这也符合小麦赤霉病的抗性以抗扩展为主的理论。     

甘蓝型油菜菌核病抗性的遗传分析

利用牙签接种和花瓣接种鉴定了甘蓝型油菜DH821（抗）×DHBao604（感）组合P₁、P₂、F₁、BC₁、BC₂、F₂ 6个世代群体菌核病的抗性，通过主基因-多基因混合遗传模型分析表现，牙签接种3 d的抗性受2对加性主基因+加性-显性多基因控制，BC₁、BC₂、F₂ 群体主基因遗传率为12.49%~28.48%，多基因遗传率为21.08%~27.87%；5 d的抗性由2对加性-显性-上位性主基因控制，显性及显性互作效应明显，无多基因修饰，BC₁、BC₂、F₂群体主基因遗传率为25.19%~38.69%；3~5 d的菌丝扩展抗性由2对加性-显性-上位性主基因+加性-显性多基因控制，主基因效应明显，多基因效应不明显，BC₁、BC₂、F₂ 群体主基因遗传率为0.72%~54.06%，多基因遗传率为7.34%~46.79%。花瓣接种15 d的抗性由2对加性-显性-上位性主基因+加性-显性-上位性多基因控制，2对主基因的加性效应和显性效应为－3.6051~ －3.5225，互作效应为3.5190~3.6089，主基因遗传率为0.91%~41.79%，多基因遗传率为19.32%~73.69%。     

陆地棉产量性状的遗传分析

采用加性-显性与环境互作的遗传模型,分析陆地棉8个杂交亲本和F128个组合的7个产量性状的两年试验资料,估算各项遗传方并非分量和F1、F2的杂种优势.结果表明,产量性状受加性效应和显性效应共同控制,加性×环境各产量性状均极显著,铃重、衣分、籽指还受显性×环境的极显著影响,7项产量性状的广义和狭义遗传率均达到极显著水准.     

水稻收获指数遗传及其与主要农艺性状的相关研究

应用完全双列杂交的遗传设计,以5个各具特性的水稻品种为材料,对收获指数的遗传进行研究。结果表明,收获指数的一般配合力（GCA）效应、特殊配合力（SCA）效应和反交（R）效应均达极显著水平,其方差比为2.595∶1.232∶1;F₂群体收获指数从低到高呈连续的近正态分布,表现数量性状的遗传特点;在加性显性模型中加性效应和显性效应达极显著值,狭义遗传力和广义遗传力分别为40.17%、67.94%。遗传相关分析表明,收获指数与结实率显著正相关,与穗长、千粒重和生物量显著负相关,由于穗长、千粒重有较高的遗传力,因此在早代对穗长、千粒重进行选择能间接改良收获指数。初步明确水稻收获指数是一个由多基因控制的数量性状,符合加性显性模型,遗传以加性效应为主,显性效应和其它效应（如反交效应）也起一定的作用,遗传力较高,可在早期分离世代进行选择。上述的结果将为水稻新品种选育提供理论依据。     

不同锌离子活度下水稻锌高效基因型农艺特性的遗传分析

本试验以耐低锌基因型和锌敏感基因型水稻为材料, 采用双列杂交, 选择耐低锌基因型和锌敏感基因型水稻在缺锌条件下反应差异较明显的总干重、地下部干重、地上部干重、叶龄、株高、根长等性状在不同锌离子活度下的相对值研究了水稻锌高效基因型农艺性状的遗传特性, 结果表明: 研究性状的显性方差都达显著和极显著水平, 在总方     

小麦品种赤霉病抗性的遗传研究

利用8个不同抗性小麦品种双列杂交的F1及其亲本,以赤霉病病粒率为抗性指标,研究了小麦赤霉病抗性的遗传。结果表明,参试品种间存在3～4对赤霉病抗性基因的差异,苏麦3号、宁麦9号和扬麦158具有较多控制赤霉病抗性遗传的显性基因,对于减少它们杂交后代的病粒率有较高的一般配合力。小麦赤霉病抗性符合加性-显性模型。赤霉     

Genetic analysis of mechanisms associated with inheritance of resistance to sheath rot of rice

Understanding genetic mechanisms controlling inheritance of disease resistance traits is essential in breeding investigations targeting development of resistant genotypes. Using North Carolina design II, 32 F₁ hybrids were generated by crossing eight susceptible to four resistant parents and submitted for field evaluation. The analysis of general and specific combining ability (GCA and SCA) indicated involvement of additive and non‐additive gene action controlling inheritance of horizontal resistance to sheath rot of rice. High GCA/SCA ratio and high heritability estimates revealed additive effects and were more predominant than none additive ones. The level of dominance indicated dominant genes was more important than recessive genes. Estimates of GCA and SCA analysis suggested that crop improvement programmes should be directed towards selection of superior parents or good combiners, emphasizing on GCA. As far as source of resistance is concerned, most promising genotypes were Cyicaro, Yunertian and Yunkeng. The predominance of additive genetic effects together with the relevance of dominant genes suggested possibilities of improving the resistance by introgression of resistance genes through recurrent selection coupled with phenotypic selection.     

同源四倍体水稻农艺性状的遗传分析

与二倍体水稻相比,同源四倍体水稻杂种具有强大的生物学优势,目前对同源四倍体水稻数量性状的遗传规律及存在较强优势的遗传基础还不清楚。此研究利用一套4×12不完全双列杂交的亲本和F1 2个世代的同源四倍体材料,采用加性-显性模型和统计分析方法,分析同源四倍体水稻农艺性状的遗传规律。结果表明,同源四倍体农艺性状受到遗传主效应与基因型×环境互作效应共同控制;其中株高、穗长以显性效应为主,剑叶宽以加性效应为主,有效穗数和剑叶长性状以显性×环境互作效应为主;株高、穗长和剑叶宽的HN和HB均分别比HNE和HBE大,表明这3个性状的选择效果受环境的影响较小;有效穗数和剑叶长的HN相对较小,HNE相对较大,说明这两个性状的选择效果因环境而不同。此研究为在杂种配制和后代选择中有效地利用同源四倍体新种质提供理论依据。     

Response of Rice (Oryza sativa L.) Tillering to Sub-ambient Levels of Ultraviolet-B Radiation

The negative impact of enhanced ultraviolet‐B (UV‐B) radiation has been demonstrated for rice, but few studies have examined the effects of low UV‐B radiation on rice growth and physiology. The objective of this study was to determine the effects of low UV‐B radiation on rice physiology with special emphasis on tiller initiation and development in two popular US rice cultivars, ‘Cocodrie’ and ‘Clearfield 161 (CL161)’. Plants received no natural UV‐B radiation because of the UV‐absorption characteristics of the greenhouse glass, hence UV‐B was artificially supplied by supplemental UV‐B lighting. Plants were grown in soil collected from research plots, and were exposed to UV‐B radiation of 0, 4 (sub‐ambient) or 8 kJ m⁻² day⁻¹ (ambient) for 29 days in one experiment and 87 days in a second experiment. ‘Cocodrie’ had no differential response among 0, 4 and 8 kJ m⁻² day⁻¹ UV‐B treatments for all the parameters measured except for plant height, which showed 5% decrease at ambient UV‐B conditions. For ‘CL161’ sub‐ambient UV‐B radiation exposure decreased vegetative tiller production (25%) and total panicle dry weight (15%). The decrease in tiller production was not due to a decrease in carbohydrate content or increase in auxin content under the low UV‐B radiation.     

培育水稻恢复系抗稻褐飞虱基因导入系和聚合系

稻褐飞虱是水稻的主要虫害之一,培育优良的抗性基因聚合系对于防治稻褐飞虱具有重要的意义.本研究通过回交、分子标记辅助选择和接虫鉴定三者相结合的办法,将抗稻褐飞虱基因Bph3和Bph24(t)分别导入主栽杂交水稻恢复系广恢998、9311、R15、明恢63、R29中,最终获得遗传稳定的Bph3导入系32份和Bph24(t)...     

Mo17抗玉米丝黑穗病的基因效应分析

在人工接种条件下研究了玉米丝黑穗病重要抗源Mo17在不同感病背景下的基因效应差异。两背景下不同世代间玉米抗丝黑穗病程度存在极显著差异，F1和F2的病株率介于双亲之间，偏向与抗病亲本，均无超亲优势，F1与双亲回交，后代的病株率基本偏向于回交亲本；玉米抗丝黑穗病的遗传分别符合六参数和四参数模型，其遗传贡献中主要以加性和显性效应为主，但在黄早四背景下表现为超显性且存在明显的上位效应，而3788背景下加性、显性效应相当，且仅存在加性、显性上位效应；以Mo17为抗病亲本组合的抗病性至少由1对抗性基因控制，估计的基因对数为0.48~1.03。     

Combining ability of cassava genotypes for cassava mosaic disease and cassava bacterial blight, yield and its related components in two ecological zones in Ghana

Breeding for resistant genotypes is the best strategy to offset the destructive effects of cassava mosaic disease (CMD) and cassava bacterial blight (CBB). Two sets of diallel parents were selected for the forest and the savannah ecological zones in Ghana based on good levels of resistance to CMD and CBB. Both sets were crossed in a half-diallel design. The first set of seven progenitors and their 21 F1 progenies were planted in a randomised complete block design (RCBD) with three replications in two different locations for two seasons in the forest ecology. The second set of five progenitors and their 10 F1 progenies were planted in a RCBD with three replications in two locations in the coastal savannah ecological zone of Ghana. Both experiments were evaluated for CMD and CBB resistance, fresh root yield, dry root yield, root number, harvest index, dry matter content, plant height at maturity and height at first branching, levels of branching and plant vigour. Results of the combined analysis of variance revealed that the environment effect was significant for all the traits. General combining ability and specific combining ability effects were significant for most of the traits. Narrow sense heritability was significant for plant vigour, root number, CMD and CBB in both the zones. CMD and root number also had a predictability ratio of close to one, indicating the importance of additive gene effects.     

Differential Response of Southern US Rice (Oryza sativa L.) Cultivars to Ultraviolet‐B Radiation

Elevated ultraviolet‐B (UV‐B; between 290 and 320 nm) radiation, because of depletion of the stratospheric ozone layer, is one of the major environmental factors influencing plant metabolic processes and yield. The southern US rice cultivars contribute greatly towards US rice production, but the effects of elevated UV‐B radiation on these cultivars are not well known. The objective of this study was to determine the effects of elevated UV‐B radiation on leaf photosynthetic rate (P_n), membrane stability, pollen viability, phenolic concentration and yield of eight commercially popular southern US rice cultivars (five inbred cultivars and three hybrids). Plants were grown in a temperature‐controlled greenhouse in Beaumont, TX, USA, and were exposed to UV‐B radiation of 0, 8 or 16 kJ m^?2 day^?1 for 90 days. For most of the cultivars, plants grown under 8 or 16 kJ UV‐B radiation showed significant decreases in P_n, membrane stability, pollen viability, and yield compared with the plants grown under an UV‐B‐free environment, whereas there was a significant increase in leaf phenolic concentration under 16 kJ UV‐B radiation. The hybrid ‘Clearfield XL729’ performed best among the selected southern US rice cultivars under 16 kJ UV‐B radiation.     

水稻核不育系柱头性状的主基因+多基因遗传分析

柱头性状是影响水稻不育系异交繁殖和杂交水稻制种产量的重要性状。为创制长柱头、高外露率的水稻温敏核不育系提供遗传信息,调查了短柱头、低外露率的粳型光温敏核不育系7001S和长柱头、高外露率的温敏核不育系紫泰S及其杂交、自交获得的F_1、F_2群体(350个株系)和F_2:3群体(320个株系)的4个柱头性状,分析了4个性状之间的相关性,并运用主基因+多基因混合遗传模型,对2个世代4个性状进行了遗传分析。结果表明,4个柱头性状间均表现出极显著正相关,相关系数介于0.262和0.895之间。柱头长度、花柱长度、柱头和花柱总长度(以下简称柱花总长度)均表现出受2对主效基因和微效基因共同控制,除F_2群体中柱花总长度的2对主基因表现为等加性效应和等显性效应外,其余均表现为加性-显性-上位性效应,3个性状均表现出以主基因间的上位性效应为主;F_2群体柱头外露率受2对加性-显性-上位性主基因+多基因控制,而F_2:3群体则表现为受1对加性-显性主基因+多基因控制,以主基因间的加性效应为主。2个世代中的4个柱头性状均以主基因遗传为主。