Effect of the Rht-D1 dwarfing locus on Fusarium head blight rating in three segregating populations of winter wheat

Fusarium head blight (FHB) is one of the major fungal diseases in wheat throughout the world. To control FHB severity, breeding genetically resistant varieties is thought to be the most promising strategy. In wheat breeding programmes, short cultivars predominantly carrying the Norin 10 derived semi-dwarfing allele Rht-D1b ( Rht2 ) are preferred worldwide because of higher achievable grain yields and lower risk of lodging. This study was conducted to determine the influence of different alleles at the Rht-D1 locus on FHB reaction. Three winter wheat populations were produced by crossing rather susceptible varieties 'Biscay', 'Pirat' and 'Rubens' carrying mutant-type allele Rht-D1b with the more resistant varieties 'Apache', 'Romanus' and 'History' containing the Rht-D1a wild-type allele ( rht2 ). The 190, 216 and 103 progeny of the F₄-derived populations were assayed for the presence of Rht-D1a or Rht-D1b , plant height, and mean FHB rating after spray inoculation at flowering time with a highly aggressive isolate of Fusarium culmorum . Comparably, high mean FHB severities ranging from 28% to 49% for all population × environment combinations were achieved, with significant genotypic variation for FHB rating and plant height within all populations. Both traits were negatively correlated with r ranging from −0.48 to −0.61 in the complete populations. However, within the subpopulations homozygous for one or other height allele these correlations decreased considerably. The Rht-D1b semi-dwarfing allele resulted in 7–18% shorter plants, depending on the population, but a considerably increased FHB reaction of 22–53%. Nevertheless, significant genotypic variance for FHB resistance remained in all tested Rht-D1b subpopulations indicating that selection for moderately FHB resistant genotypes within agronomically beneficial Rht-D1b genotypes is still feasible.     

The effect of the ‘Golden Promise’ dwarfing gene on partial resistance to leaf rust and powdery mildew in spring barley

Summary F₂-plant progenies, derived from seven crosses between susceptible erectoides breeding lines and conventional, nutans breeding lines with partial resistance to leaf rust incited by Puccinia hordei Otth., derived from Vada x Cebada Capa, were examined in a field and a glasshouse experiment. In the field experiment, the nutans plant progenies generally were more resistant to leaf rust and powdery mildew than the erectoides progenies. In the glasshouse experiment, the components of partial resistance to leaf rust of six erectoides and six nutans progenies derived from one cross were studied. The nutans progenies generally had lower infection frequencies than erectoides progenies with a similar infection level in the field experiment. The variation for leaf rust and powdery mildew infection in the field was similar for the nutans and erectoides progenies. This suggests that erectoides lines with a fairly high level of partial resistance to leaf rust and powdery mildew can be selected from these populations.     

山东主栽矮化中间砧苹果抗旱性主成分及隶属函数分析

使用抗旱性的砧木是解决目前苹果生产干旱问题的有效手段,但目前对于普遍使用的矮化中间砧并没有一个科学的抗旱性的评价。本研究利用主成分分析和隶属函数相结合的方法对山东普遍使用的矮化中间砧M26、SH40、MM106、M9和GM256（品种‘‘烟富3’’,基砧平邑甜茶）的抗旱性进行了综合评价。通过对干旱胁迫相关生理生化参数相对含水量(RWC)、脯氨酸(Pro)、丙二醛(MDA)、可溶性糖、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、叶绿素(Chl)含量进行主成分分析,利用隶属函数和权重计算求得综合评价值进行分析评价。结果表明：矮化中间砧M26、SH40、MM106、M9、GM256的综合评价值分别为：0.757、0.716、0.457、0.263、0.136,由此确定山东地区普遍使用的矮化中间砧抗旱性强弱顺序为：M26 >SH40 >MM106>M9 >GM256。     

渭北旱塬矮化富士苹果幼树N,K营养状况分析

采用311-A最优混合设计,以有机肥、无机肥(mN∶mP2O5∶mK2O=1∶0.7∶1)和补充灌水量为主要因子,通过田间试验和室内叶分析,对无病毒矮化红富士苹果树体的N,K营养状况进行了研究。结果表明,在渭北旱塬南缘,红富士苹果幼园不施肥或施肥不足,均会造成树体N,K营养缺乏,成为影响幼树生长发育的主要限制因子,其中以N素缺乏尤为严重;在中量施肥条件下,N,K营养均为非限制性因素,但补充灌水能提高养分的有效性。对树体生长、发育和营养状况进行综合分析后确定,渭北旱塬南缘矮化红富士幼树的最适施肥量、灌水量分别为:有机肥20000～24536kg/hm2,无机肥N,K2O均为376.90～501.2kg/hm2,P2O5263.80～350.84kg/hm2,平水年补充灌水量为24.8～61.8mm,丰水年可不进行补充灌水。     

矮秆基因Rht8和Rht13对冬小麦水分利用效率的效应比较

以含有矮秆基因Rht8的冬小麦品种晋麦47与Rht13的供体Magnif M1杂交获得的含有不同矮秆基因的重组自交系ZX_(44)(Rht8)、ZX_(34)(Rht13)、ZX_(33)(Rht8+Rht13)和ZX_(16)(rht)为材料,在田间和盆栽试验条件下主要研究了矮秆基因Rht8和Rht13对不同水分状况下冬小麦水分利用效率(WUE)和产量的影响。结果表明:含有矮秆基因的三个品系ZX_(34),ZX_(44)和ZX_(33)与高秆对照系(ZX16)在田间和盆栽同一水分条件下的耗水量差异不显著。田间与盆栽的干旱条件下四种小麦品系的产量趋势均为ZX_(44)ZX_(34)ZX_(16)ZX_(33),灌水条件下均为ZX_(34)ZX_(44)ZX_(33)ZX16。田间干旱条件下四种小麦品系的产量WUE为ZX_(44)ZX_(34)ZX_(16)ZX_(33),灌水条件下为ZX_(44)ZX_(34)ZX_(33)ZX16。盆栽两种水分条件下的产量WUE趋势均为ZX_(34)ZX_(44)ZX_(16)ZX_(33)。ZX_(34)品系与ZX_(44)品系的产量WUE在田间相同水分条件下、盆栽干旱条件下差异不显著,而在盆栽灌水条件下差异显著;两者的收获指数在田间和盆栽试验的干旱和灌水条件下均较高。田间相同水分处理下四种小麦品系的生物量WUE差异不显著,而盆栽相同水分条件下为ZX_(34)ZX_(44)ZX_(33)ZX_(16)。综上,引入Rht8基因和Rht13基因均能明显提高产量和WUE。在配合不断选育的基础上,含有Rht13基因的冬小麦是半干旱地区小麦高WUE育种中的另一材料。     

不同矮化中间砧对苹果苗光合特性的影响

【目的】对2种矮化中间砧盆栽嫁接苹果苗的光合指标和叶绿素荧光参数变化进行研究,揭示苹果中间砧对嫁接植株光合机理的影响。【方法】以八棱海棠为基砧,M9和M26为矮化中间砧,2年生"长富2号"为嫁接材料,设八棱海棠同龄砧嫁接"长富2号"为对照,分析M9和M26矮化中间砧对嫁接苗比叶重、叶绿素和类胡萝卜素含量、光合指标(净光合速率、胞间CO2浓度、气孔导度、蒸腾速率)及日变化、叶绿素荧光参数和其日变化的影响。【结果】M9和M26矮化中间砧嫁接苗的净光合速率显著高于对照嫁接苗,而气孔导度、胞间CO2浓度和蒸腾速率较低。M9和M26矮化中间砧嫁接苗的Fm、Fv/Fm和Fv/Fo显著低于对照嫁接苗,但qN、ETR、NPQ却高于对照嫁接苗。经过中午的强光和高温后,M9和M26矮化中间砧嫁接苗的Fo显著下降,NPQ和ETR明显升高,而对照嫁接苗的Fo显著上升,NPQ和ETR升高不明显,Fo的升高表明对照嫁接苗的PSⅡ反应中心由于强光破坏而明显失活。【结论】矮化中间砧影响下的苹果苗防御强光破坏的机制与对照嫁接苗不同,矮化苗的光能调节能力更强,其因具有较高的净光合速率而早产。     

水稻显性矮秆新基因的RAPD分析

利用RAPD标记对中粳水稻新品种突变体Y98149中鉴定出的显性矮秆新基因进行研究。结果表明,在150对随机引物中,两对引物SAl530和SB930在亲本和近等基因池(均由10个高秆或矮秆植株组成)之间表现出多态性。用这两对引物对高秆和矮秆的F2群体的300个单株进行连锁分析,表明SAl530和SB930与新矮秆基因的连锁距离分别为15．3cM和9．3cM,两个RAPD标记位于同一侧。     

M系苹果矮化砧木与砧穗组合研究

对江苏省丰县的M系苹果矮化中间砧(基砧为八棱海棠)M26、MM106、M9,以及矮化自根砧MM106、M7富士苹果园进行了调查,从树体的生长发育、枝类的组成、果实的产量和品质等方面进行了综合评价,除M9中间砧外,其余矮砧嫁接的富士苹果树均是比较适宜的优良砧穗组合.此外,还指出了江苏丰县苹果矮砧密植存在的主要问题,并提出...     

Analysis on the Dwarfing Genes in Zhepi 1 and Aizao 3： Two Dwarfing Gene Donors in Barley Breeding in China

Inheritance of plant height was studied in the two dwarfing gene donors, Zhepi 1 and Aizao 3, in barley breeding in China. Using direct cross and para-back-cross methods, allelic tests were carried out not only between the dwarfing genes in Zhepi 1 and Aizao 3, but also with br, uzu, denso, or sdwl and the six novel dwarfing genes that have been recently identified in barley in China. The results showed that the plant height was attributed to Mendelian inheritance of a recessive dwarfing gene both in Zhepi 1 and Aizao 3. The dwarfing genes carried by the two cultivars were the same, but different from the three known and the six novel dwarfing genes. On the basis of the present study, only two dwarfing genes have been used in barley breeding in China since 1950.     

秋水仙素诱导甜高粱‘FH59’种子变异效应研究

为了研究秋水仙素水溶液对甜高粱‘FH59’种子的诱变效应,创制优质甜高粱种质资源。本实验利用不同浓度的秋水仙素水溶液(0.05%、0.1%、0.15%、0.2%)浸泡甜高粱种子24、31、48 h,统计苗期变异率,并对成活植株进行大田鉴定。研究结果表明,秋水仙素诱变效果受到处理时间、药剂浓度以及二者交互作用的显著影响,在24 h,0.15%诱变条件下诱变效果最佳,幼苗变异效果显著。M₂代田间鉴定发现株高、生育期、穗长、籽粒颜色、锤度等主要农艺性状的突变体,变异类型丰富,尤其是发现的大量的矮化、早熟突变体对甜高粱亲本的改良作用明显。