Genetic Analysis of Cryotolerance in Cotton During the Overwintering Period Using Mixed Model of Major Gene and Polygene

The joint analysis of the mixed genetic model of major gene and polygene was conducted to study the inheritance of cryotolerance in cotton during the overwintering period.H077（G.hirsutum L.,weak cryotolerance） and H113（G.barbadence L.,strong cryotolerance） were used as parents.Cryotolerance of six generation populations including P1,P2,F1,B1,B2,and F2,from each of the two reciprocal crosses H077×H113 and H113×H077 were all investigated.The results showed that cryotolerance in cotton during the overwintering period was accorded with two additive major genes and additivedominance polygene genetic model.For cross H077×H113,the heritabilities of major genes in B1,B2,and F2 were 83.62,76.84,and 90.56%,respectively;and the heritability of polygene could only be detected in B2,which was 7.76%.For cross H113×H077,the heritabilities of major genes in B1,B2,and F2 were 67.42,68.95,and 83.40%,respectively;and the heritability of polygene was only detected in F2,which was 6.51%.In addition,the whole heritability in F2 was always higher than that in B1 and B2 in each cross.Therefore,for the cryotolerance breeding of perennial cotton,the method of single cross recombination or single backcross should be adopted to transfer major genes,and the selection in F2 would be more efficient than that in other generations.

Inheritance Analysis of Bolting Associated Traits Using Mixed Major Gene Plus Polygene Model in Brassica rapa

[ Objective ] This study aimed to analyze the inheritance of bolting associated traits in Brassica rapa, which will provide useful information in a breeding program for late-bolting or bolting-resistant cultivars of Chinese cabbage. [ Method] Three phenotypic measurements, bolting index, flowering time, days to 5 cm elongated stalk, respectively were used for inheritance analysis of six generations, P, （bolting resistant inbreed line ）, P2 （vernalization independent type） and their filial generations F1 , B1, B2 and F2, using the mixed major-gene plus polygene inheritance model. [ Result] The two traits, bolting index and days to 5 cm elongated stalk, both were controlled by two major genes with additive-dominant-epistatic effects （ B-1 model） in hybrid. The flowering time was controlled by one major gene with addltive-dominant effects plus additive-dominant-epistatic effects （D model）. The heritability of the major genes in B1, B2 and F2 were 96.22%, 93.33%, 93.55% for bolting index, 70.68%, 70.68%, 70.64% for flowering time, 79.44%, 79.55%, 79.38% for days to 5-cm elongated stalk, respectively, but no polygene heritability was detected in BI, B2 and F2 generation. It indicated that the bolting trait in Brassica rapa was controlled by one or tow major genes. [ Conclusion] This implied that in the genetic improvement for bolting resistant trait major gene was a main factor. It is fit for early selection and environment factor should be mentioned.

Genetic Analysis of Stripe Disease Resistance in Rice Restorer Line C224 Using Major Gene plus Polygene Mixed Effect Model

The inheritance of stripe disease resistance in a rice restorer line C224 was analyzed using the mixed effect model of major gene plus polygene for quantitative traits.In addition,the resistance was investigated in seven crosses of C224 with maintainer lines.The results showed that the stripe resistance of C224 was controlled by two major genes with additive-dominance-epistasis effects plus polygenes with additive-dominance effects （E-1 model）.These two genes had additive effects of-12.47% and-24.75%,respectively,showing negative dominance effects.There were significant epistasis and interaction effects between the two major genes.The heritability of the two major genes was 92.12%,while that of polygenes was 2.74%,indicating that the stripe resistance had dominant major gene effect.Of the seven crosses,five displayed high or medium resistance to the stripe disease.

Genetic Analysis of Embryo Production Frequency in Wheat × Maize Cross

A DH population derived from C49S-87/01Y1-1069 was used to study the inheritance of wheat haploid embryo production frequency（EPF） in wheat × maize cross with the mixed major gene and polygene inheritance model of quantitative traits. The results showed that the EPF of wheat × maize cross was controlled by two dominant epistatic genes and polygene with gene effects of 1.95 for the first major gene, 6.69 for the second one and 2.80 for the polygene. The inheritability of major genes was as high as 72.09%, suggesting that the differences in EPF among wheat materials were mainly influenced by genotype. However, non-genetic factors were still important, especially for wheat materials with low EPF.

Study on Inheritance Mechanism of Tomato Fruit Firmness

[Objective] This study aimed to investigate the inheritance mechanism of tomato fruit firmness.[Method] Two tomato cultivars significantly different in fruit firmness were selected for investigation of the inheritance mechanism of tomato fruit firmness using combination analysis of six generations （P1,P2,F1,F2,B1 and B2）.[Result] The results indicated that the heredity of tomato fruit firmness was consistent with the additive-dominant model controlled by one pair of major genes; the additive effect （d）,dominant effect （h） and degree of dominance （h/d） of major genes were 17.37,-7.96 and-0.46,respectively,showing positive additive effect and incompletely dominant-negative effect; the hereditability of major gene effect in B1,B2 and F2 generation was 88.59％,45.81％ and 85.62％,respectively.[Conclusion] The heredity of fruit firmness was controlled by one pair of major gene,showing significant additive effect and dominant effect.

Genetic Analysis on Plant Height in Rice in Different Growing Seasons

[Objective] The aim was to carry out the genetic analysis on plant height of rice（Oryza sativa L.）cultivated in different seasons.[Method] Three rice parents with great difference in plant height including CB1（83.1 cm）,CB4（105.5 cm）and CB7（115.6 cm）were chosen to construct two parental combinations：CB1×CB4 and CB7×CB4,and the corresponding filial generations P1,F1,P2,B1,B2 and F2 were obtained.The 6 populations were planted in middle and late seasons respectively to measure their height traits.The Akaike＇s information criterion（AIC）of the mixed major gene and polygene model was used to indentify the existence of major genes affecting quantitative traits in B1,B2,F2 populations.When the major genes existed,the genetic effects of the major genes and polygenes and their genetic variance were estimated through segregation analysis.[Result] One additive major gene plus additive-dominance polygenes was the most fitted genetic model for the trait in all B1,B2,F2 populations in two planting seasons.The heritability values of the major genes varied from 38.63% to 78.53% and those of polygenes varied from 1.72% to 36.04%,and the total heritability values were 45.52-92.93%.The additive effect d value of the two genetic populations under two planting seasons was-4.56,-9.16,-7.19,and-9.38,respectively,as suggested that additive effect of the major genes would decrease the express of the plant height trait.[Conclusion] The heritability of plant height trait was affected by planting seasons and the combinations clearly as a whole.

小麦面筋相关性状的主基因+多基因遗传模型分析

【目的】通过小麦面筋相关性状的主基因+多基因遗传模型分析,探析小麦湿面筋含量、干面筋含量和面筋指数的遗传规律,为我国长江中下游麦区红皮强筋专用小麦品种选育提供理论参考。【方法】以苏麦6号×扬97G59为亲本构建的双单倍体(DH)群体(共189个家系)为材料,采用主基因+多基因遗传分离分析方法对小麦湿面筋含量、干面筋含量和面筋指数进行遗传模型分析。【结果】湿面筋含量在句容试点MX2-ED-A模型为最佳模型,受到2对显性上位性效应主基因和加性效应微效多基因控制,主基因遗传率为74.18%,多基因遗传率为24.35%,但在扬州试点MX2-IE-A模型为最佳模型,受到2对抑制效应主基因和加性效应微效多基因控制,主基因遗传率为7.41%,多基因遗传率为90.60%。对于干面筋含量,在句容试点MX2-ED-A模型为最佳模型,受到2对显性上位性效应主基因和加性效应微效多基因控制,主基因遗传率为38.24%,多基因遗传率为61.61%,但在扬州试点MX2-IE-A模型为最佳模型,受到2对抑制效应主基因和加性效应微效多基因控制,主基因遗传率为5.65%,多基因遗传率为94.04%。面筋指数在句容试点MX2-AI-AI模型为最佳模型,受到2对加性上位性效应主基因和加性上位性效应微效多基因控制,主基因遗传率为66.34%,多基因遗传率为33.55%,但在扬州试点MX2-DE-A模型为最佳模型,受到2对重叠效应主基因和加性效应微效多基因控制,主基因遗传率为42.05%,多基因遗传率为57.62%。【结论】小麦干面筋含量、湿面筋含量和面筋指数均表现为数量性状的特点,受多基因的控制,且存在环境效应。干面筋含量和湿面筋含量的遗传主要受2对显性上位性或抑制效应主基因+多基因的控制;面筋指数的遗传受2对加性上位性或重叠效应主基因+多基因的控制。

辣椒株高主基因+多基因混合遗传模型分析

株高是辣椒重要农艺性状之一,直接影响辣椒的抗倒性和丰产性。为明确辣椒株高的遗传规律,以株高较矮的B1-2和株高较高的D50为亲本,采用植物数量性状主基因+多基因混合遗传模型方法对P1、P2、F1、B1、B2和F26个世代的株高进行了遗传分析。结果表明,辣椒株高最适合遗传模型符合E-1模型,即受2对加性-显性-上位性主基因+加性-显性多基因控制。株高的2对主基因加性效应相等,均为3.4087,显性效应值分别为1.3698和-0.7346。B1、B2和F2分离群体中主基因遗传率分别为34.18%、67.48%、66.45%,多基因遗传率分别为46.84%、12.85%、21.99%。试验结果表明,辣椒株高受主基因和多基因共同控制,受环境影响较小。

番茄苗期耐低温性主基因-多基因联合遗传分析

为研究番茄苗期耐低温性的遗传规律,选取耐低温性不同的2份番茄高代自交系材料XC-1、XC-2于花期配制F1,再配制BC1、BC2、F2世代,对6个世代的幼苗同时进行低温处理,日间温度14℃,光照处理9 h(08:00—17:00),光照度为30μmol·m^(-2)·s^(-1),夜间7℃(17:00至翌日08:00)不进行光照,相对湿度为75%,共处理15 d。处理结束后调查耐低温性分级。采用主基因-多基因联合遗传分析方法研究耐低温性的遗传。结果表明,番茄幼苗耐低温性的遗传受2对加性主基因+加性-显性多基因控制,主基因的遗传率在BC1、BC2、F2世代分别达57.357%、54.441%、68.463%,多基因的遗传率分别达6.607%、10.602%、2.994%。主基因与多基因的影响较大,该性状的选择可在早代进行。

花生网斑病抗性遗传分析

花生网斑病严重影响花生的产量和品质。为探究花生网斑病抗性遗传机制,本研究利用植物数量性状主基因+多基因混合遗传模型对感病品种豫花22和抗病品种冀农99杂交得到的F2:3群体进行了网斑病抗性遗传分析。对病斑面积比和病情指数的分析结果表明,花生网斑病抗性主要由1对主基因加性-显性效应控制,主基因遗传率分别为76.72%和65.45%,一对主基因加性效应值(da)分别为8.11和21.95。本研究可为花生网斑病抗性育种提供一定的理论基础。

茄子果形性状遗传研究

为探究2个茄子组合品种的果形指数遗传规律,选用3种果形指数差异显著的高代自交系茄子(长筒、高圆和短筒果形)为材料,构建了2个杂交组合(组合Ⅰ:长筒×高圆,组合Ⅱ:高圆×短筒),采用六世代联合分析法研究果形指数的遗传规律。结果表明:果形指数遗传属于数量性状,2个组合果形指数遗传模型均适于E-3模型,即2对加性主基因+加性-显性多基因模型,组合Ⅰ表现出一负一正的主基因加性效应,组合Ⅱ表现出2个负向的主基因加性效应,2个组合多基因的加性效应均大于显性效应,说明以加性效应遗传为主。组合Ⅰ中B1、B2世代主基因遗传率大于多基因遗传率,以主基因遗传为主,F2世代多基因遗传率大于主基因遗传率,以多基因遗传为主,B2世代环境效率较高,为48.49%;组合Ⅱ中B1、B2分离世代的主基因遗传率大于多基因遗传率,以主基因遗传为主,F2的多基因遗传率大于主基因遗传率,以多基因遗传为主,B1和B2世代遗传受环境因素影响较大,环境效率高于40%。

陆海渐渗系F_(2)群体纤维品质性状数量遗传分析

本试验以陆海染色体片段渐渗系C14为父本、冀棉262为母本构建F_(2)分离群体,并对群体的纤维品质性状进行数量遗传分析,利用主基因-多基因遗传分析模型对F_(2)世代上半部平均长度、断裂比强度、马克隆值、整齐度指数和伸长率进行遗传分析,以确定各性状的最适遗传模型并掌握其遗传规律,为田间选育遗传稳定的棉花纤维品质性状提供参考。结果表明,5个纤维品质性状中,上半部平均长度、马克隆值、整齐度指数和伸长率符合遗传模型,受主基因控制,而断裂比强度不存在主基因,受微效多基因控制。上半部平均长度符合B-1模型,受2对主基因控制,为加性-显性-上位性混合遗传模型,主基因遗传率为62.56%;马克隆值和伸长率均符合A-1模型,为受1对主基因控制的加性-显性混合遗传模型,主基因遗传率分别为9.96%和27.17%;整齐度指数符合B-6模型,为受2对主基因控制的加性-显性等效混合遗传模型,主基因遗传率为43.64%。上半部平均长度主基因遗传率最高,说明该性状在后代遗传中受环境影响较小,遗传较稳定,可以在低世代直接进行选择;而马克隆值主基因遗传率低于10%,说明该性状在后代中遗传不稳定,受环境影响较大,需要在高世代进行选择。

糯玉米种子活力性状的主基因+多基因混合遗传分析

【目的】探索鲜食型糯玉米种子活力的遗传模型,为糯玉米种子活力研究提供理论基础。【方法】以种子活力有显著差异的糯玉米自交系N34(P_(1))和N56(P_(2))为亲本,配制F1、B_(1)、B_(2)、F_(2)群体,利用主基因+多基因混合遗传模型分析方法,对种子活力3个相关指标(发芽势、电导率和活力指数)的遗传模型进行分析。【结果】鲜食糯玉米发芽势最佳遗传模型为2对加性-显性-上位性主基因+加性-显性-上位性多基因混合遗传模型,B_(1)、B_(2)和F_(2)主基因遗传率分别为66.62%,49.10%和92.94%;电导率最佳遗传模型为1对加性-显性主基因+加性-显性多基因混合遗传模型,B_(1)、B_(2)和F_(2)主基因遗传率分别为57.75%,57.96%和65.14%;活力指数最佳遗传模型是2对加性-显性-上位性主基因+加性-显性多基因混合遗传模型,B_(1)、B_(2)和F_(2)主基因遗传率分别为66.49%,48.02%和89.49%。3个性状均以主基因遗传为主。【结论】在育种实践中,对糯玉米种子活力的遗传改良和选择可在低世代进行,同时可采用聚合回交或轮回选择来积累有效修饰基因和微效基因,以提高育种效率。

糯高粱F_(2)群体农艺性状数量遗传分析

【目的】探明糯高粱F_(2)群体农艺性状数量遗传规律,为酒用高粱新品种选育提供参考。【方法】选取糯质高粱基础材料湘10721和青稞洋进行组配获取F_(2)群体,通过主基因-多基因分离分析,筛选各性状最优模型,并计算主基因遗传率。【结果】糯高粱F_(2)的旗叶长、茎粗、株高均符合2MG-ADI,为加性-显性-上位性混合遗传模型,主基因遗传率分别为99.90%、99.99%、99.72%;穗长符合2MG-CD,为完全显性遗传模型,主基因遗传率为95.83%;穗柄长符合2MG-A,为加性混合遗传模型,主基因遗传率为99.79%;旗叶宽遗传模型为0MG,即不受主基因控制,为受微效多基因控制的性状。【结论】糯高粱F_(2)的旗叶长、茎粗、株高、穗长、穗柄长5个性状的遗传率较高,可以在育种早代进行选择,旗叶宽属微效多基因控制的性状,遗传不稳定,受环境影响较大,在育种高世代进行选择更为准确。

水稻稻曲病抗性的主基因+多基因混合遗传模型分析

稻曲病是由稻曲病菌引起的水稻真菌病害,目前已上升为我国水稻主要病害之一,探明水稻稻曲病的抗性遗传机制对制定抗病育种策略具有现实指导意义。本研究以病情指数为指标,利用高效引发稻曲病人工接种方法对来自抗病亲本IR28(籼稻)与感病亲本大关稻(粳稻)组合的亲本及其衍生的F10代重组自交系群体(RIL)进行抗病性评价,采用数量性状的主基因+多基因混合遗传模型对抗性的遗传模型进行判别与遗传参数的估计。结果表明,水稻稻曲病抗性的遗传除受主基因控制外还受多基因的影响,符合E-1-3遗传模型,即2对主基因+多基因混合遗传模型,2对主基因间表现为等加性作用,加性效应为11.41;主基因遗传率为76.67%,多基因遗传率为22.86%,抗性遗传存在明显的主基因效应。提示抗稻曲病育种时不仅要考虑主基因对抗病性的作用,也不能忽视基因对抗性的影响。

小麦雌性育性的主基因+多基因混合遗传分析

选用普通小麦中3种不同生态型育性正常品种与雌性不育系XND126杂交构建3个F2组合,连续两年对3组合P1、P2、F1和F2雌性育性进行调查,利用植物数量性状主基因+多基因混合遗传模型的4世代联合分析方法分析了小麦雌性育性的遗传。结果表明:小麦雌性育性受两对主效基因+多基因联合控制,两对主效基因之间存在互作效应。

玉米P_(25)自交系抗锈病基因的遗传分析及SSR分子标记定位

以玉米南方型锈病免疫自交系P2 5和感病自交系F3 4 9及F1、F2 、B1和B2 为材料 ,采用主基因 多基因混合遗传模型研究了P2 5的抗病遗传规律。结果表明 :自交系P2 5的抗病基因为一主基因 ,表现为加性效应 ,没有检测出多基因 ,其在F2 、B1和B2 群体的遗传率分别为 81 88%、38 14 %和 5 5 1%。利用SSR分子标记技术 ,以组合P2 5×F3 4 9的F2 :3 家系作为构图群体 ,构建了玉米SSR遗传连锁图谱 ,并将玉米抗南方型锈病基因定位于 10号染色体上 ,与phi0 5 9标记的遗传距离为 5 8cM。

小麦纹枯病抗性的主基因+多基因遗传分析

以病情指数为指标,利用牙签接菌法对ARZ×扬麦 158衍生的F6 代重组自交系群体 (RIL)进行纹枯病抗性评价,并采用植物数量性状主基因+多基因混合遗传模型分离分析法,研究该群体抗纹枯病基因的遗传规律。结果表明,这一群体中小麦纹枯病的抗性符合两对连锁主基因遗传模型(B 2 1),主基因间表现为加性 加性×加性上位性作用,重组率为 0 178 7。在两对主基因中,效应较大的 1对加性效应为 10 10%,效应较小的 1对加性效应为 2 32%,两对主基因的遗传率中等偏高,为 72 31%。提示抗纹枯病育种应重视主基因的利用。

普通丝瓜果实性状的遗传分析

应用植物数量性状主基因+多基因混合遗传模型对普通丝瓜品种50-5(黑籽短圆筒)×20-4(桂林水瓜)杂交组合6个世代群体的5个果实性状(果柄长、果长、果径、果形指数和单果质量)进行了联合分析,结果表明:50-5×20-4组合果柄长的遗传符合2对加性-显性-上位性主基因+加性-显性多基因遗传模型,其B1、B2和F2群体遗传率(主基因+多基因)分别为68.49%、70.53%和82.07%,环境方差占总表型方差的比例分别是31.50%、29.47%和17.92%;果长遗传符合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,其B1、B2和F2群体遗传率(主基因+多基因)分别为68.85%、84.55%和81.68%,环境方差占总表型方差的比例分别是31.15%、15.44%和18.32%;果径遗传符合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,其B1、B2和F2群体遗传率(主基因+多基因)分别为65.23%、73.06%和73.82%,环境方差占总表型方差的比例分别是34.62%、26.94%和26.13%;果形指数遗传符合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,其B1、B2和F2群体遗传率(主基因+多基因)分别为65.23%、62.80%和78.89%,环境方差占总表型方差的比例分别是34.76%、37.19%和21.11%;单果质量遗传符合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,其B1、B2和F2群体遗传率(主基因+多基因)分别为70.71%、85.35%和89.64%,环境方差占总表型方差的比例分别是29.29%、14.64%和10.36%。果柄长性状的主基因遗传率较小,宜采用个体选择法(基因型选择法),宜在分离晚世代进行选择;果长、果径、果形指数和单果质量性状的主基因遗传率较大,宜采取混合选择法(表型选择法),可在分离早世代进行选择;且宜对5个果实性状进行综合选择。5个果实性状的环境方差占总表型方差的比例均较高,故在育种过程中要尽量采取措施以减少环境影响。

栽培大豆耐盐性的主基因+多基因混合遗传分析

选用栽培大豆南农1138-2(耐盐)、南农88-31(较耐盐)和Jackson(盐敏感)配制的南农1138-2×南农88-31和南农88-31×Jackson等2套组合,通过P1、P2、F1、F2和F2:3苗期植株耐盐性调查,利用主基因+多基因混合遗传模型联合分离分析了栽培大豆耐盐性的遗传规律。结果表明南农88-31×Jackson和南农1138-2×南农88-31耐盐性遗传均符合加性-显性-上位性多基因遗传模式。在高世代选择耐盐性植株的效率较高,从F2:3估计,南农88-31×Jackson组合的NaCl耐性微效基因遗传率为82.13%;南农1138-2×南农88-31组合的耐盐性微效基因遗传率为67.47%。