A test of supposed mutants for stem rust resistance in wheat

Summary Eight stem rust (Puccinia graminis tritici Eriks. and Henn.) resistant lines (designated TICENA lines) that had been selected by Veiga et al. (1981) following gamma radiation of BH-1146 wheat (Triticum aestivum L.) were studied. Six of the lines were resistant to race 15B-1 of stem rust and susceptible to race 56, and proved to carry the gene Sr7a. TICENA 4 carries two unidentified genes, each giving resistance to one of the two races. TICENA 10 carries Sr6, Sr7a and an unidentified gene giving resistance to race 56 but not 15B-1. The results raise doubts about the supposed origin of the lines as mutants.     

磷化氢熏杀其抗性害虫实仓试验

用磷化铝片对储藏在房式仓（仓容５１６ｍ３）中的４００ｔ散装小麦进行熏蒸。储 不小麦水分为１１．５％,储藏平均温度为２９．３℃,小麦用ＰＶＣ（厚度０．１２５ｍｍ）复盖。熏 蒸期间用磷化氢检测管测定ＰＨ3浓度。采用１．０３ｋｇ磷化铝片（可释放０．３４ｋｇ磷化氢） 分成小包进行熏蒸,磷化氢最高值为 １． ０ｍｇ／Ｌ。熏蒸 １６天的 ＣＴ值为 ２１３ｍｇ· ｈ／Ｌ。用 敏感和抗性品系的米象和谷蠹进行生物试验表明．熏蒸１个月后所有的成虫都死亡;熏 蒸４２天所有中度抗性的谷蠹没有发现Ｆ１代成虫出现．米象的印和蛹不能发育为成虫。     

条锈病影响下冬小麦叶绿素含量的高光谱估计

叶绿素含量是在小麦长势监测中是非常重要的评估内容，尤其是在小麦受到病害影响的情况下，准确估计其叶绿素含量，有助于合理进行灾害评价。遥感高光谱技术为获取植物的生理参数提供了丰富的数据来源。笔者使用襄樊地区实测获取的受条锈病影响的小麦高光谱数据，利用回归分析的方法建立了受条锈病影响的小麦叶绿素含量与其高光谱的关系模型。经验证，模型有较好的精度。     

黑麦草叶蛋白提取工艺研究

采用酸化和加热相结合的方法，研究了从黑麦草中提取叶蛋白的最佳工艺条件，并分析了黑麦草叶蛋白中的氨基酸组成。结果表明黑麦草叶蛋白提取的最佳工艺条件为pH4.0，料水比1：2，凝聚温度为70℃，加热时间5min。该条件下提取的叶蛋白含量可高达70.48%。氨基酸分析显示黑麦草叶蛋白中人体必需氨基酸、鲜味氨基酸和药效氨基酸分别占总氨基酸的40.3247%、22.2439%和77.5609%。黑麦草叶蛋白具有很好的营养、保健和药用价值。     

Evaluation of seedling and adult plant resistance to stem rust in European wheat cultivars

A total of 105 European wheat cultivars were assessed for seedling and adult plant resistance (APR) to stem rust using an array of Australian isolates of Puccinia graminis f. sp. tritici. Twenty-seven cultivars were susceptible at both seedling and adult plant growth stages. Twelve catalogued seedling stem rust resistance genes (Sr7b, Sr8a, Sr8b, Sr9b, Sr9g, Sr11, Sr15, Sr17, Sr29, Sr31, Sr36 and Sr38) were detected in the remaining cultivars, and 13 cultivars carried additional seedling resistance genes that could not be postulated with the isolates used. Low levels of APR to stem rust were found in the cultivars Artaban, Forno, Mec, Mercia, Pandas and Vlada. Although the genetic identity of this APR was not determined, it was clear that the only designated stem rust APR gene Sr2 was not present in any of the cultivars tested based on the absence of the linked traits seedling chlorosis and pseudo black chaff. One of these cultivars, Forno, is believed to carry the leaf rust APR gene Lr34, previously reported to be associated with improved resistance to stem rust. A detailed genetic characterisation of the APRs in these cultivars will be needed to understand their modes of inheritance and relationships with catalogued stem rust resistance genes. Such knowledge may help in developing cultivars with effective gene combinations that confer higher levels of protection.     

A 192bp allele at the <Emphasis Type="Italic">Xgwm261</Emphasis> locus is not always associated with the <Emphasis Type="Italic">Rht8</Emphasis> dwarfing gene in wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

The height-reducing gene Rht8 was introduced into Italian wheats by breeder Nazareno Strampelli from the Japanese landrace Akakomugi, and has been widely used in wheats adapted to southern and eastern European conditions. Following identification of a close linkage to Rht8, microsatellite marker Gwm261 has been used extensively to screen large numbers of diverse international germplasm. A 192bp allele at this locus has been taken as “diagnostic” for Rht8 and used to infer the international distribution of Rht8. In this paper, we report several instances of cultivars and mapping populations that vary for the presence of the 192bp allele at the Xgwm261 locus (Xgwm261 ₁₉₂ ), but with no associated reduction in height, suggesting a lack of association with Rht8. For instance, in the population derived from a cross between Sunco (Rht-B1b, Xgwm261 ₁₆₅ ) and Tasman (Rht-D1b, Xgwm261 ₁₉₂ ), there were significant height differences associated with the segregation of Rht-B1b and Rht-D1b, but no height differences between Xgwm261 genotypes. Similar results were obtained in a population derived from the cross between Molineux (Rht-B1b, Xgwm261 ₁₉₂ ) and Trident (Rht-D1b Xgwm261 ₂₀₈ ). In contrast, the cross between Trident and Chuanmai 18 (Xgwm261 ₁₉₂ ) gave significant height effects at both the Rht-D1 and Xgwm261 loci, with no epistatic interaction between loci. Chuanmai 18 is closely related to the Strampelli wheat Mara (ancestrally derived from Akakomugi) and is therefore likely to carry Rht8. The old Japanese cultivar Norin 10, used by Norman Borlaug to introduce Rht-B1b and Rht-D1b into Mexican wheats, also has a 192bp allele at the Xgwm261 locus, and the sequence of the amplified product is identical to that of Akakomugi. We suggest that the widespread use of Norin 10-derived germplasm during and after the Green Revolution introduced a second haplotype into international germplasm, in which Xgwm261 ₁₉₂ has no association with Rht8. Therefore, the presence of Xgwm261 ₁₉₂ is only indicative of Rht8 in wheat cultivars that have inherited this allele from Akakomugi or a Strampelli wheat ancestor.     

油菜花后光合面积变化及其与产量的关系

油菜光合面积变化与干物质积累和产量的关系结果表明，初花期，盛花期叶面积系数（LAI）与干物质积累和产量呈抛物线关系，终花期LAI，终花期和成熟期角果皮面积系数（PAI）与干物质积累和产量呈显著线性正相关。花后LAI下降幅度越大，花后干物质净增量越低，花后PAI上升幅度加大，花后干物质净增量和产量增加，高产油菜的光合面积系数变化以LAI在初花期达最大值，盛花期略为下降，盛花后缓慢下降，花后PAI迅速增加为宜，施肥能有效调节油菜光合面积系数的变化，提高花后LAI和PAI，延缓花后叶面积的下降速度。     

西南地区小麦种质资源白粉病抗性的全基因组关联分析

为了有效利用我国西南地区小麦抗白粉病种质资源,于2012―2013年在贵州贵阳、贵州赫章和四川绵阳以及2013―2014年在贵州贵阳对主要来自西南地区的120个小麦品种(系)进行了白粉病抗性鉴定,并利用小麦90K芯片进行全基因组关联分析。抗病性鉴定结果显示,36个品种(系)在四个环境下均表现出抗性,其中大部分品种(系)来自贵州省。全基因组关联分析发现,16个SNP位点与白粉病抗性显著相关,分别位于1A、1D、2A、3A、4B、5B、6A、6D和7B染色体上,其中位于6AS染色体重要区段上的3个SNP位点(Jagger_c4823_169、Tdurum_contig55201_928和Tdurum_contig12215.89)的遗传距离小于1cM,在四个环境中均与白粉病抗性显著相关。相关分析表明,这3个SNP位点与 Pm21分子标记(SCAR1265)紧密连锁。     

反射光谱法估计小麦叶片表皮蜡质含量的初步研究

为了探讨利用冠层反射光谱技术估计小麦叶片表皮蜡质含量的可行性,以小麦高叶片表皮蜡质含量材料2912与低叶片表皮蜡质含量品种普冰201和晋麦47及其杂交构建的F2:3株系为材料,通过氯仿提取称重法测定了小麦抽穗期的旗叶表皮蜡质含量,并采用FieldSpec 3测定了冠层反射光谱,分析小麦冠层反射光谱与叶片表皮蜡质含量之间的关系。结果表明,三个亲本以及株系间蜡质含量差异显著。高蜡质材料的可见光波段反射率整体高于低蜡质材料,短波长波段光谱反射率与叶片表皮蜡质含量相关性较高。以550和675nm波长的反射光谱为基础的单波/差值指数[R550/(R550-R675)]能较好地反映小麦叶片蜡质含量,两F2:3群体拟合模型的r2值分别为0.761和0.679,回归方程分别为y=0.07x-0.575和y=0.088x-1.481。     

玉米低钾耐性性状的主基因+多基因遗传分析

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,以玉米缺钾症状叶片数为指标,对1个耐低钾玉米自交系T和2个低钾敏感玉米自交系S1和S2配制成的2个组合的P1、P2、F1、B1、B2和F2世代进行遗传分析,研究明确玉米耐低钾性状的遗传机制。结果表明,玉米低钾耐性遗传在2个组合中都由1对加性+加性-显性多基因控制;主基因遗传率(F2)平均为60.43%,多基因遗传率(F2)平均为15.35%;T×S1组合的遗传变异占表型变异值为80.20%,T×S2组合的遗传变异占表型变异值为71.35%,表明耐低钾性状以主基因遗传为主。育种应用上可以在低世代进行这一目标性状的选择。