甜玉米品质性状的主基因+多基因遗传分析

对甜玉米品质性状进行主基因+多基因遗传分析,为甜玉米品质改良提供理论依据。用果糖含量、膳食纤维含量和维生素C含量差异显著的甜玉米自交系配制杂交组合T77（高值亲本）×T15（低值亲本）。以该组合F2代群体为试验材料,对其果糖含量、膳食纤维含量和维生素C含量等3个品质性状进行测定,利用主基因+多基因混合遗传模型分析3个性状的最适遗传模型及相关遗传参数。试验表明,果糖含量的最适模型为A-1,是受1对主基因控制的加性-显性遗传模型,主基因遗传率为76.4%;膳食纤维含量和维生素C含量的最适模型同为B-1,表明这2个性状符合2对主基因控制的加性-显性-上位性混合遗传模型,主基因遗传率分别为63.6%和64.7%。在育种实践中,对甜玉米果糖含量、膳食纤维含量和维生素C含量的遗传改良和选择,可在早期世代进行,同时要注意一定的环境因素,采用聚合回交或轮回选择的方法来积累微效基因以提高育种效率。     

冬瓜果实形状的主基因+多基因遗传分析

果实形状是评价冬瓜外观品质的一个重要指标。开展冬瓜果实形状遗传研究、分析其遗传机制,为冬瓜优质育种提供依据。本研究以圆球形冬瓜YO-16和圆柱形冬瓜KX-8为亲本,构建4个世代(P1, P2, F1,F2)遗传群体,并结合主基因+多基因混合遗传模型对冬瓜果实的纵径、横径和果形指数进行遗传及相关分析。结果表明,果形指数与果实纵径、果实横径间呈极显著相关性,其中果形指数与果实纵径的相关性最大。果实纵径的最适合遗传模型是MX2-AD-AD,符合2对加性-显性主基因+加性-显性多基因混合遗传模型,其主基因和多基因遗传率分别为87.008 5%和4.796 8%;果实横径和果形指数的最适合遗传模型都是MX2-ADI-AD,符合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,其主基因遗传率分别为82.623 7%和89.403 5%,多基因遗传率分别为1.765 9%和1.020 3%。上述性状的主基因遗传率均远大于多基因遗传率,以主基因遗传为主。因此,在冬瓜优质育种过程中要重视利用主基因,应在早期世代对果形性状进行选择。     

烟草主要农艺性状的主基因+多基因遗传分析

本研究以烤烟品种‘云烟97’和‘变异云烟97’为亲本,分别构建P1、P2、F1和F24个世代遗传群体,利用植物数量性状主基因+多基因混合遗传模型方法对烟草的株高、节距、叶数和茎围进行遗传及相关分析。结果表明,株高分别与节距、叶数间呈极显著正相关,与茎围间呈显著正相关;而节距与叶数间则呈现极显著负相关。株高、节距和叶数3个性状具有相同的最优遗传模型,即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(MX2-ADI-AD),其主基因遗传率分别为95.225 8%、94.285 4%和99.177 1%,多基因遗传率分别为4.774 2%、5.568 4%和0.822 9%;茎围性状符合2对加性-显性主基因+加性-显性多基因混合最优遗传模型(MX2-AD-AD),其主基因和多基因遗传率分别为90.314 6%和9.685 4%。上述性状均受主基因+多基因混合遗传模型控制,主基因遗传率均高达90%以上且远大于多基因遗传率,受环境影响可以忽略。因此,在烟草高产育种过程中针对上述农艺性状的定向选择宜在早期世代进行。     

爆裂玉米百粒重性状的主基因+多基因混合遗传分析

应用植物数量性状主基因+多基因混合遗传模型多世代联合分析方法,研究了爆裂玉米吉爆902(吉812×吉704)的P1、P2、F1、B1:2、B2:2和F2:3 6个世代百粒重的遗传.结果表明:百粒重性状的遗传适合D-2模型,即1对加性主基因+加性-显性多基因模型.爆裂玉米的百粒重是由1对独立主基因控制的加性遗传,主基因的...     

12个水稻光温敏核不育系的ISSR标记鉴定及遗传分析

应用ISSR技术对12个水稻光温敏核不育系进行DNA指纹分析,筛选到13个生态性丰富的引物,共获得169个多态性DNA片段,选择其中的3个引物扩增出的8个多态性DNA片段可作为鉴定标记,能够正确区分供试的12个水稻光温敏核不育系。根据多态性片段的有无,将鉴定标记转换为数字1和0,建立了12个水稻光温敏核不育系相应的ISSR标记鉴定识别码。由Nei‘s,遗传距离创建的聚类分析表明,12个材料被聚为两大类群,4个梗型不育系聚为一类,其余8个籼型不育系聚为另一类,在籼稻群内,3个来源于安农S-1的不育系单独聚为一类,与来源于农垦58S的材料有明显的遗传差异。研究结果表明,ISSR标记具有简便、快速、多态性丰富等优点,可用于构建DNA指纹图谱,进行品种鉴定和遗传分析。     

甘蓝型油菜苗期耐淹性状主基因+多基因遗传分析

长江中下游是中国油菜主产区,该地区油菜播栽期间雨水多,易产生湿害,造成产量下降。所以研究甘蓝型油菜苗期耐淹性的遗传规律,对选育耐淹性强油菜新品种,提高油菜产量意义重大。本文应用甘蓝型油菜品种WR-4 (耐淹)和WR-5 (不耐淹)杂交后代衍生的6个世代(P₁、F₁、P₂、B_1:2、B_2:2、F_2:3)群体为材料,全淹6 d后去水恢复生长,去水后第7天调查死苗率,以此为耐淹性指标,于2012和2013年对6个世代群体家系进行耐淹性鉴定。应用植物数量性状主基因+多基因混合遗传模型多世代联合分析方法对耐淹性进行遗传分析。结果表明,2个年度该家系群体苗期耐淹性的最适遗传模型分别是E-0和B-3,即2对加性-显性-上位性主基因+加性-显性-上位性多基因和2对加性主基因模型。由此可见,该家系群体甘蓝型油菜苗期耐淹性主要受2对主基因控制,主基因存在加性、显性和上位性效应。当有显性效应存在时(2012年),主基因显性效应值|h_a|=0.3475,|h_b|=0.0069,大于主基因加性效应值|d_a|=|d_b|=0.0036。B_1:2、B_2:2和F_2:3群体的主基因遗传率(h²_mg),2012年分别为36.25%、61.40%和61.84%,平均为53.16%;2013年分别为8.30%、30.48%和43.13%;平均为27.30%。2年平均,环境变异占表型变异的59.77%。上述结果表明,甘蓝型油菜苗期耐淹性受2对主基因型控制,但环境对耐淹性状的表型影响较大。F_2:3家系群体苗期耐淹性遗传率较高,因此育种上可在早期世代对耐淹性状进行选择。     

茄子果实形状的主基因+多基因遗传分析

果实形状是园艺作物商品性的主要指标之一。明确茄子果实形状的遗传规律可为开发相关分子标记以及选育消费者喜欢的果形新品种提供依据。本研究以卵圆茄BC01和长条茄Rf为亲本，构建P₁、P₂、F₁、F₂世代遗传群体，利用主基因+多基因混合遗传模型分析方法对果实纵径、横径和果形指数进行遗传分析。结果表明，茄子果实纵径、横径和果形指数之间呈极显著相关性，F₂代的果实纵径、横径和果形指数均呈双峰偏态分布。果实纵径由1对加性-显性主基因控制，遗传效应以加性效应控制为主，主基因起增效作用，在F₂代的遗传率为73.41%；果实横径由2对等加性主基因控制，主基因起减效作用，在F₂代的遗传率为90.99%；果形指数由1对加性主基因控制，在F₂代的遗传率为81.46%。     

瓠瓜果实形状的主基因+多基因遗传分析

为研究瓠瓜果形的遗传规律,本研究以瓠瓜梨形果自交系(H07)为母本,扁圆形果自交系(H14A)为父本,构建六世代(P₁, P₂, F₁, F₂, BC₁P₁, BC₁P₂)群体,对瓠瓜果实横径、纵径及果形数进行主基因+多基因遗传分析。结果表明,瓠瓜的果实纵径与果形指数具有极显著相关性,三个性状均呈偏态向右分布;果实纵径和果形指数最适遗传模型为MX2-ADI-ADI,受2对加性-显性-上位性主基因+加性-显性-上位性多基因控制,主基因遗传率分别为77.360 3%和85.775 6%;果实横径最适遗传模型为MX2-ADI-AD,受2对加性-显性-上位性主基因+加性-显性多基因控制,主基因遗传率为51.0076%。以上结果为深入研究瓠瓜果形遗传机制及定位提供依据。     

水稻光温敏核不育系的ISSR和SSR遗传分析比较

本研究应用ISSR和SSR技术建立了24个水稻光温敏核不育系的DNA指纹图谱，利用13个ISSR引物和20对SSR引物，分别获得174个多态性片段和62个多态性片段，平均每个ISSR引物检测到13．38个多态性片段，远远高于SSR引物的检测率。根据遗传距离进行的聚类分析表明，利用这两种标记所得的聚类结果十分相似，24个材料被聚为粳型，偏籼型和籼型三个类群，在籼型不育系类群内，又可明显的分成三个亚类群，其中7个安农S-1衍生的不育系聚为一类，与农垦58S衍生的不育系有明显的遗传差异。根据两种标记计算的遗传距离及其遗传关系，所得的结果仍有一些差异，但总体趋势是一致。研究结果表明，ISSR和SSR标记适用于构建DNA指纹图谱，进行分类鉴定和遗传分析。     

Production and testing of plants regenerated from protoplasts of photoperiod sensitive genic male sterile rice (Oryza sativa L.)

Plants were regenerated from protoplasts isolated from embryonic suspension cultures of N5047S, a photoperiod sensitive genic male sterile (PGMS) Japonica rice line. Flow cytometric analyses of nuclear DNA content identified some tetraploid regenerates whose agronomic traits could be distinguished from diploid regenerates. Pollen and female fertility of diploid protoplast-derived clones grown under different light and temperature conditions was compared. A promising PGMS protoplast clone, ZAU11S, was developed from these clones. Its male sterility was confirmed as a photoperiod × temperature interaction type. This revised version was published online in July 2006 with corrections to the Cover Date.     

水稻圆粒基因RS的鉴定和定位

阐明水稻籽粒大小相关基因的遗传和分子机制对水稻产量形成具有重要意义。利用甲基磺酸乙酯(ethyl methanesulfonate, EMS)诱变粳稻品种宁粳3号筛选获得圆粒突变体round seed (rs)。遗传分析表明,突变体rs圆粒表型由单隐性核基因控制。颖壳扫描电镜观察发现,rs籽粒变圆主要是细胞数目改变导致的。在突变体rs中,细胞周期相关基因的表达较野生型显著升高。将RS定位在第3染色体短臂标记RM3413与N3-5之间,物理距离约589 kb。RS突变影响BR信号途径,改变了粒型相关基因的表达。本研究有助于阐明水稻籽粒发育的分子机制。     

蓖麻株高性状主基因+多基因遗传分析

本研究选用蓖麻YC2×YF1高、矮秆组合的2组6世代群体(P1、P2、F1、B1、B2和F2),对株高性状进行了主基因+多基因混合遗传模型分析。结果表明,蓖麻株高受1对主基因和多基因共同控制。2组群体在B1、B2和F2三个分离世代中主基因遗传率分别为37.05%/49.57%、30.51%/34.48%和43.98%/43.64%;主穗位高和主茎节数均受2对主基因和多基因共同控制,且主基因的互作效应显性效应加性效应。3个分离世代中,2组群体主穗位高主基因遗传率分别为67.91%/92.72%、86.89%/92.13%和60.18%/66.87%,主茎节数主基因遗传率分别为91.83%/91.50%、35.22%/63.37%和85.76%/94.58%。主茎节长由多基因控制,遗传率分别为47.64%/47.64%、38.87%/38.87%和25.25%/52.71%。以上遗传模式决定了蓖麻杂种后代株高、主穗位高和主茎节长的正向超亲遗传,而主茎节数则倾向于低值亲本。因此,主穗位高和主茎节数可以作为株高的早期间接选择指标。     

小麦重要产量性状的主基因+多基因混合遗传分析

以单株产量等为代表的重要性状是选育小麦高产良种的主攻目标性状,分析小麦重要产量性状的数量遗传特性,为深入研究其遗传机制提供依据。本研究选用品冬34为母本(P₁)和BARRAN为父本(P₂)配置杂交组合,在2年4个环境下应用主基因+多基因混合遗传模型方法对该组合单世代(P₁、P₂、RIL_7:8、RIL_8:9)单株产量、千粒重、株高、穗下节间长、旗叶上节间长和分蘖数进行遗传及相关分析。结果表明,除千粒重和分蘖数外,其余性状间均显著或极显著相关,穗下节间长与旗叶上节间长平均相关系数达0.91 (P≤0.001)。最优遗传模型对于单株产量是4对加性上位性主基因+多基因遗传模型,其主基因加性效应值分别为3.78、2.89、–6.18和0.15,多基因遗传率为86.23%;对于千粒重是2对互补作用主基因+加性效应多基因混合遗传模型,多基因加性效应值是22.37,主基因遗传率为66.96%,多基因遗传率为28.25%;对于株高是2对累积作用主基因+加性作用多基因混合遗传...     

Combining ability and heterosis over environments for yield and yield components in two-line hybrids involving thermosensitive genic male sterile lines in rice (Oryza sativa L.)

Presence of substantial heterosis and economic hybrid seed production are two most desirable components for success of any commercial hybrid breeding programme. Thermosensitive genic male sterile (TGMS) lines of rice, in this regard, have tremendous potential in realizing further quantum jump in yield and economical hybrid seed cost. Analyses for combining ability and heterosis over optimum (120N : 60P₂O₅ : 40K₂O kg/ha) and high (200N : 90P₂O₅ : 60K₂O kg/ha) fertility environments for six traits were made in 2 years (2001 and 2002) using 120 hybrids of inter‐ and intra‐subspecific nature derived from hybridization of 30 elite indica TGMS lines and four cultivars, viz., ‘Pant Dhan 4’ and ‘Ajaya’ (I = indica), ‘Taichung 65’ (J = japonica) and ‘IR 65598‐112‐2’ (TJ = tropical japonica) in line × tester mating design. Predominance of non‐additive genetic variance suggested good prospects of hybrid breeding. Pooled analysis revealed highly significant variances for lines, general combining ability (GCA), specific combining ability (SCA) and line x tester. TGMS line 365‐8S was the best general combiner for all the six traits including grain yield. Trend of relative mid‐parent heterosis for grain yield, panicle length, grain number per panicle and earliness in flowering was I/TJ > I/J > I/I. For panicle number per plant and 1000‐grain weight, trends were I/TJ > I/I > I/J and I/I > I/TJ > I/J, respectively. Grain yield recorded heterosis of 49.3%, 71.9% and 92.7% for I/I, I/J and I/TJ hybrid groups respectively. Effect of environments on the hybrid performance indicated better response of hybrids at high fertilizer dose. Study suggests greater prospects of combining improved japonica and tropical japonica germplasms having wide compatible gene with indica TGMS lines for exploitation of intersubspecific heterosis.     

Genetic analysis and fine mapping of tms9, a novel thermosensitive genic male‐sterile gene in rice (Oryza sativa L.)

Two‐line hybrid rice as a novel hybrid breeding method has huge potential for yield increasing and utilization of intersubspecific heterosis, and it is of major significance for the food security of rice‐consuming populations. Zhu1S is a thermosensitive genic male‐sterile line of rice with low critical temperature and excellent combining ability, which has been widely exploited as a female parent in Chinese two‐line hybrid rice breeding. Here, genetic mapping in F₂ populations was used to show that its male sterility is inherited as a single recessive gene and that responsible gene (termed tms9) lies on the short arm of chromosome 2. A high‐resolution linkage analysis which was based on the Zhu1S/R173 F₂ population found that the thermosensitive genic male‐sterile gene tms9 of Zhu1S was fine mapped between insertion–deletion (Indel) markers Indel 37 and Indel 57, and the genetic distance from the tms9 to the two markers was 0.12 and 0.31 cM, respectively. The physical distance between the two markers was about 107.2 kb. Sequence annotation databases showed that the two Indel markers (Indel 37 and Indel 57) were located on two BAC clones (B1307A11 and P0027A02). There are sixteen open reading frames (ORF) present in this region. The results of this study are of great significance for further cloning tms9 and molecular marker–assisted selection.     

Molecular mapping of a new genic male-sterility gene causing chalky endosperm in rice ( Oryza sativa L.)

A genic male-sterility gene newly induced by chemical mutagenesis, tentatively designated as ms-h(t), was located on the molecular map of rice and tested for its effect on chalky endosperm. Bulked segregant analysis was used to determine the chromosomal location of the ms-h(t) locus by screening four to five RFLP markers per chromosome. After confirming that the gene was located on chromosome 9, twenty-four RFLP markers from chromosome 9 were surveyed for polymorphism in the parents of the mapping population. Of these, eleven markers were mapped around the ms- h(t) locus. RG451 and RZ404 flanked the ms-h(t) gene, at 2.5cM and 3.3cM, respectively. Heterozygous F2 to F4 progenies were tested for co- segregation of male-sterility and chalky endosperm and it was revealed that ms-h(t) might have a pleiotropic effect on chalky endosperm. This mutant would be a good biological material to characterize the biochemical mechanism of male sterility and related pleiotropic effects. Further studies should be needed to know the usefulness of this mutant for hybrid seed production. This revised version was published online in July 2006 with corrections to the Cover Date.     

籼粳交稻米品质性状杂种优势的遗传分析

用胚乳性状遗传模型和分析方法对籼粳交稻米品质性状的杂种优势进行了遗传分析,结果表明：各品质性状都具有一定的杂种优势,其中碱消值和蛋白质含量的优势较强。直链淀粉含量和胶稠度的优势较弱。不同性状杂种优势的遗传原因不同,直接显性和母体显性对杂种优势的贡献大小因性状而异,但总的来说,母体显性对籼粳杂种Ｆ２籽粒品质性状的杂种优势具有重要的意义,细胞质效应对部分性状（如胶稠度、蛋白质含量）的群体平均优势有一定     

水稻温敏型叶片白化转绿突变体tsa2的表型鉴定与基因定位

水稻温敏型叶色突变体是研究植物光合作用、叶绿体结构和功能以及温度影响叶绿体发育的理想材料。利用甲基磺酸乙酯(EMS)诱变籼型水稻(OryzasativaL.)三系保持系西农1B,从其后代中筛选到一个突变性状稳定遗传的温敏型叶片白化转绿突变体tsa2 (temperature-sensitive green-revertible albino 2)。与野生型相比, tsa2突变表型受温度影响, 22°C条件下萌发的野生型幼苗表型正常,而tsa2幼苗完全白化,且约40%白化苗死亡,存活白化苗的光合色素含量、光合速率均显著降低,成熟期主要农艺性状均显著变劣;在28°C下萌发的tsa2幼苗叶片呈浅绿色并伴有白条纹,其光合色素含量显著降低,光合速率及主要农艺性状差异较小; 32°C下萌发的tsa2幼苗叶片无明显差异。透射电镜观察显示,与野生型相比,tsa2在22°C下叶肉细胞中无叶绿体或存在异常发育叶绿体(尚未分化出基粒和基层),在28°C下部分叶肉细胞含少量发育完整的叶绿体,在32°C下叶肉细胞数量及形态均正常。实时荧光定量PCR(qRT-PCR)分析表明,与野生型相比,tsa2突变体中部分光合色素代谢途径基因、叶绿体发育相关基因及光合作用相关基因的表达水平呈不同程度变化。遗传分析表明, tsa2突变表型受一对隐性核基因控制, TSA2被定位于第5染色体SSR标记S5-57和S5-119之间,物理距离为718 kb。本研究为水稻遗传改良及研究温度影响叶绿体发育机制奠定了基础。