Advanced Backcross QTL Analysis for the Whole Plant Growth Duration Salt Tolerance in Rice（Oryza sativa L.）

Salinity is a major factor limiting rice yield in coastal areas of Asia. To facilitate breeding salt tolerant rice varieties, the wholeplant growth duration salt tolerance（ST） was genetically dissected by phenotyping two sets of BC2F5 introgression lines（ILs） for four yield traits under severe natural salt stress and non-stress filed conditions using SSR markers and the methods of advanced backcross QTL（AB-QTL） analysis and selective introgression. Many QTLs affecting four yield traits under salt stress and nonstress conditions were identified, most（〉90%） of which were clustered in 13 genomic regions of the rice genome and involved in complex epistasis. Most QTLs affecting yield traits were differentially expressed under salt stress and non-stress conditions. Our results suggested that genetics complementarily provides an adequate explanation for the hidden genetic diversity for ST observed in both IL populations. Some promising Huanghuazhan（HHZ） ILs with favorable donor alleles at multiple QTLs and significantly improved yield traits under salt stress and non-stress conditions were identified, providing excellent materials and relevant genetic information for improving rice ST by marker-assisted selection（MAS） or genome selection.     

基于性状和分子标记的高丹草近等基因系的分离研究

【目的】以株高等表型性状和分子标记为基础,从高粱×苏丹草的F6:7重组自交系群体中分离株高、叶片数2个性状及对这2个性状有效应的分子标记的近等基因系,为精确定位性状的QTL及分析QTL的作用提供有用的遗传材料。【方法】利用高粱314A×棕壳苏丹草的F2:3遗传作图群体的后代材料建立重组自交系群体F6:7,对株高、叶片数2个性状,采用基于性状和基于分子标记的近等基因系分离法,分别找出差异显著的株系和杂合的株系。将2种方法找出的共同株系再进行SSR标记,剔除杂合株,其余2种纯合子基因型即为该性状的近等基因系(NIL)。【结果】在重组自交系RIL-105和RIL-85家系内分别分离出了株高和叶片数的近等基因系。在重组自交系RIL-127家系内分离出了互作位点umc1714—umc2247的近等基因系。【结论】利用分离得到的这些近等基因系可进一步精确定位性状的QTL位点和分离QTL位点及对互作位点(上位性)的遗传效应进行分析。     

Epistasis and Maternal Effect in Resistance to Puccinia coronata Cda. f. sp. avenae Eriks in Oats （Avena sp.）

The objective of this paper was to investigate the mode of heredity for resistance in oats （Avena sp.） to crown rust caused by Puccinia coronata Cda. f. sp. avenae Eriks, Eight generations of 2 crosses were used to estimate genetic effects and narrow-sense heritability （NSH）. Separate generation means analysis （GMA） indicated a complex gene action controlling this trait with additive, dominance, epistatic and maternal effects （ME）. The genetic model which assumed no epistasis and no ME did not accurately describe the resistance to P. coronata. In both crosses, the digenic epistatic model with ME was sufficient to explain variation in generation means for isolate CRec58 and isolate CRec46. Additive dominance and epistatic components were negative in most cases, suggesting that gene effects contributed more to the resistance than to the susceptibility. The estimated values of NSH were 15-99% depending upon the cross and isolates. The results indicated that appropriate choice of maternal parent and recurrent selection would increase resistance to crown rust in oats.     

籼型三系杂交水稻穗颖花数和茎秆特性的遗传分析

采用包括基因型×环境互作效应的加性 -显性 -加性×加性上位性遗传模型和统计方法 ,研究籼型三系杂交水稻穗颖花数和茎秆特性的遗传特点 .结果表明 ,所研究的 7个性状除了穗颈粗外 ,其余 6个性状均以加性效应和加性×加性上位性效应占主导地位 ,遗传率较高 ,在杂交早代选择效果较好 .穗颖花数与穗长、茎粗、茎基抗折力间具有极显著的正向加性相关关系 .另外 ,穗颖花数除了与秆型指数表现极显著的负向加性×加性上位性相关外 ,与其他 5个性状均呈极显著的正向相关关系 .在利用杂种优势方面 ,茎基抗折力和株高这两个性状较明显 ,其次为穗颖花数 ,第三为穗长和茎粗 .从对亲本的综合评价看 ,不育系以冈 4 6 A为最优 ,恢复系以明恢 6 3为最优 .     

大豆γ-生育酚的混合遗传分析与QTL定位

【目的】通过对大豆γ-生育酚进行混合遗传和QTL定位分析,了解其遗传机制,定位其主效QTL,为高γ-生育酚含量大豆品种的选育奠定基础。【方法】以栽培大豆晋豆23为母本,以山西农家品种大豆灰布支黑豆为父本杂交衍生的重组自交系作为供试群体构建遗传图谱。图谱全长2 047.6 cM,平均图距8.8 cM,包括227个SSR标记,232个标记位点。重组自交系试验群体及亲本材料分别于2011年、2012年和2015年夏季在河南省农业科学院原阳试验基地种植,冬季在海南省三亚南繁试验基地种植。田间试验采取随机区组设计,2次重复。从6个环境中每个家系选取15.00 g籽粒饱满,大小一致的大豆种子,利用高效液相色谱法定性、定量测定样品中的γ-生育酚含量。采用主基因+多基因混合遗传分离分析法,对大豆γ-生育酚含量进行混合遗传分析;采用WinQTLCart2.5复合区间作图法,对大豆γ-生育酚含量进行QTL定位分析。【结果】主基因+多基因混合遗传分析表明,γ-生育酚受2对重叠作用主基因×加性多基因控制。遗传基因分布在双亲中。三亚试验数据检测出2对主基因间上位性效应值为0.4010—0.5169和多基因的加性...     

基因型×环境互作效应对水稻茎秆抗倒性杂种优势的影响

用包括基因型×环境互作效应的加性—显性—加性×加性上位性遗传模型和统计方法 ,对水稻茎秆抗倒性杂种优势进行了研究 .结果表明 ,评价水稻茎秆抗倒性的 5个性状 (秆长、茎粗、茎基抗折力、秆型指数和抗倒指数 )的杂种优势既由基因型控制也受环境 (年份 )互作效应影响 .茎粗对环境的敏感性较弱 ,表现较低的正向群体平均优势和负向群体超亲优势 .基因型×环境互作效应影响了秆型指数和抗倒指数杂种优势表达的程度和方向 .秆长、茎基抗折力在不同环境中均表现正向基因型×环境互作效应 ,这表明随着环境的改善均可增强杂种优势     

Genetics of resistance to early blight (Alternaria solani Sorauer) in tomato (Lycopersicon esculentum L.)

The genetic nature of early blight resistance in tomato was studied in three crosses at seedling and adult plant stages. A six generation mean analysis of the cross Arka Saurabh (susceptible) × IHR1939 (resistance) and its reciprocal cross revealed that the resistance to early blight was conferred by recessive polygenes at both seedling and adult plant stages. This polygenic early blight resistance revealed the importance of additive and additive × additive gene effects at seedling stage and higher magnitude of dominance and dominance× dominance gene effects at adult plant stage. Evaluation of parents, F₁, F₂ and backcross generations of IHR1816 (resistance) × IHR1939 (resistance) revealed that the early blight resistance genes in IHR1816 (Lycopersicon esculentum NCEBR-1) and IHR1939 (Lycopersicon pimpinellifolium L4394) are independent. This revised version was published online in July 2006 with corrections to the Cover Date.     

偏分离条件下牙鲆生长性状QTL的主成分定位

本研究利用有丝分裂雌核发育建立牙鲆(Paralichthys olivaceus)双单倍体(Doubled Haploids,DH)群体,对牙鲆体重、全长、背鳍长、腹鳍长、体高、尾柄高、头高和躯干长共8组表型性状标准化处理后,进行主成分分析,得到可解释全部性状90.4%的表型主成分性状。然后,基于JoinMap 4、MapDisto、JoinMap 4-DistortedMap、MapDisto-DistortedMap构建4个连锁图谱,用偏分离标记矫正数量性状位点(Quantitative Trait Locus,QTL)基因型条件概率,采用Bayesian模型选择方法定位牙鲆表型主成分性状的加性QTL和上位性QTL。结果表明,用不同方法构建的遗传图谱和表型主成分性状QTL定位结果均有所不同。在图谱构建中,与基于JoinMap 4构建的图谱相比,基于MapDisto构建的图谱中偏分离标记的相对位置和遗传距离都发生了变化,甚至有5个偏分离标记没有被定位到相应的连锁群上;相对于基于JoinMap 4和MapDisto构建的图谱,经DistortedMap校正后的图谱中偏分离标记的相对位置没有发生变化,但是偏分离标记间遗传距离发生了变化。另外,在4个图谱中都检测到3个加性QTL,分别位于6号连锁群上,可解释表型变异的12.95%、14.85%、11.56%和11.76%,9号、22号连锁群上,具有负向加性效应;9号连锁群上,可解释表型变异的13.86%、13.27%、11.17%和11.25%,具有负向加性效应;22号连锁群上,可解释表型变异的5.68%、4.36%、4.97%和3.58%,具有正向加性效应。同时,分别检测到28对、19对、29对和20对上位性QTL,主要分布在6号、7号、9号、17号、20号和22号连锁群上,可解释表型主成分性状变异的2.19%~17.62%、2.40%~22.26%、2.08%~26.0%、3.16%~22.05%。研究结果表明,基于MapDisto软件构建、经DistortedMap软件包矫正后的图谱,定位结果更加准确,但仍需进一步验证。     

Segregation of bunch orientation in plantain and banana hybrids

Bunch orientation is an economically important trait in plantain (Musa spp. AAB group) and banana (Musa spp. AAA or ABB groups). Pendulous bunches are more symmetrical than subhorizontal, horizontal, or erect bunches and are, therefore, better adapted for transportation. Erect, horizontal, subhorizontal, and pendulous bunches were observed in segregating populations derived from crosses between plantains and bananas and among bananas. A proposed genetic model controlling this trait was tested in four populations. The true breeding diploid banana line, 'Calcutta 4' shows a pendulous bunch and has recessive alleles at three bunch orientation loci. The diploid banana cultivar 'Pisang lilin', which is heterozygous for the three loci, has a subhorizontal bunch. The triploid AAB plantain cultivar 'Bobby Tannap' has two simplex and one duplex loci, which also results in subhorizontal bunch orientation. The other plantain cultivar, 'Obino l'Ewai', which is simplex for two loci and nulliplex for the third, has a pendulous bunch due to dosage effects at the triploid level of the recessive alleles at simplex loci. Two tetraploid hybrids (TMPx 582-4 and 1187-8) have a subhorizontal bunch because of its duplex genotype for two loci and simplex genotype for the other locus. Bunch orientation might be an oligogenic trait regulated by the epistatic effects of at least three dominant loci. This revised version was published online in July 2006 with corrections to the Cover Date.