含CIMMYT种质的半外来玉米群体对丝黑穗病的抗性研究

为了研究在高纬度地区引进和利用CIMMYT玉米种质对丝黑穗病抗性的影响,采用田间人工接种方法测定了部分用CIMMYT种质Pob45和Pob46与黑龙江省骨干自交系杂交构建的半外来群体的选系对丝黑穗病的抗性。结果表明在这些含CIMMYT玉米种质的半外来群体的选系中,对丝黑穗病表现中抗及以上的占一半以上,其中高抗占35.9%。CIMMYT种质的引进总体上有利于提高黑龙江省种质资源对丝黑穗病的抗性。     

含有不同温带种质比例的玉米半外来群体选系的杂种优势研究

利用适当的温带种质对外引种质进行改良,可进一步丰富温带玉米遗传基础。以来自CI-MMYT的Pob101群体和我国主要种质的代表系为试验材料,研究不同温带种质比例的Pob101×掖478半外来群体选系与旅大红骨群和Lancaster群的杂种优势,为这些半外来群体的进一步改良和利用提供依据。结果表明,理论上含有75%温带血缘的Pob101×掖478半外来群体选系与旅大红骨群和Lancaster群的杂种优势均值均大于含有25%温带血缘的掖478×Pob101半外来群体选系与旅大红骨群和Lancaster群的杂种优势均值,在高产育种中有较大的利用潜力。     

含CIMMYT种质的改良系的改良效果研究

摘要：本研究将黑龙江省玉米自交系吉846和K10与CIMMYT种质Pob45、Pob46杂交构建半外来群体并从中选育改良系,再按原杂交种的组配形式或配制成若干改良杂交组合,对其产量和其它性状进行测定并与原杂交种进行比较,研究其产量和产量性状的变化特点与规律,分析改良的效果和进一步改良的方向,为更有效地利用外来种质特别是来自CIMMYT的热带和亚热带多数种质改良黑龙江省现有的种质资源提供参考。结果表明从半外来群体吉846×Pob45中选育的吉846改良系与K10组配的杂交组合的产量有高于同熟期对照龙单13和原组合的,部分杂交组合的株高、穗位有所降低,部分杂交组合的雄穗一级分枝数、全株叶面积、出籽率、百粒重也有较明显的改良。从半外来群体K10×Pob46中选育的K10改良系与吉846组配的杂交组合的产量都低于同熟期对照龙单13和原组合,但个别性状如百粒重、出籽率、行粒数、穗长有一定的改良效果。     

加拿大早熟群体杂交选系对玉米丝黑穗病抗性评价

为了了解加拿大早熟玉米群体杂交选系对黑龙江省主要玉米病害之一丝黑穗病的抗性水平,从而为中国北方玉米抗病育种提供优质种质资源,以80份加拿大早熟玉米群体杂交选系为材料,在哈尔滨、密山两地分别采用人工接种技术评价其对玉米丝黑穗病的抗性。结果表明,80份加拿大玉米群体杂交选系中没有高抗材料,发现SW1284等14份抗病材料,SW1084等13份中抗材料,SW1236等35份感病材料,SW1175等18个高感材料,中抗以上材料占全部鉴定材料的33.8%;杂交选系与供体双亲平均发病率相关极显著,相关系数r=0.30（r0.01,78=0.281）。     

12个外来玉米群体与我国主要种质配合力效应和杂种优势分析

国际玉米小麦改良中心(CIMMYT)和美国玉米带种质含有丰富的遗传变异, 是拓展我国玉米种质基础的重要来源。本文采用NCII遗传交配设计, 以中综5号、中综6号和中综7号综合种为测验种, 与12个外来群体配制36个组合。以郑单958为对照, 2009—2010年分别在北京顺义、山东济南和河南新乡进行产量及相关性状测定。利用Miranda Filho-Geraldi模型, 评价外来群体主要性状配合力效应及杂种优势表现。结果表明, Pob43、La Posta、Pob21、Pob32、Pob49、Pob501等群体的产量及相关性状GCA表现优良。群体Pob49、Pob501与我国PA种质, Pob32、BS29与我国PB种质, Pob43、La posta与我国D群四平头种质的遗传关系较近。因此, 在改良外来群体适应性的基础上, 可以我国A、B和D类群种质为核心, 将群体Pob21、Pob49、Pob501与A群种质, Pob32与B群种质, Pob43、La Posta与D群的四平头种质构建复合种质并进行改良, 逐步拓宽我国主要种质类群的遗传基础。     

二十个加拿大玉米群体性状表现及对丝黑穗病抗性的评价

以引进的20个加拿大玉米群体为材料,对其主要性状及玉米丝黑穗病抗性进行评价.供试群体在黑龙江省均具有较好的适应性,且生育期较短,属早熟和中早熟类型,可以在早熟玉米育种中利用.其中,群体EP9的产量及各产量构成因子等性状表现较好,可优先利用.20个群体对丝黑穗病抗性差异较大.其中,群体EP7、EP8、EP15、EP23表现为抗病,占供试材料的20%;群体EP1、EP9、EP12、EP16、EP21表现为中抗,占25%;感病群体11个,占55%,但发病率均小于21%,表明供试群体均对玉米丝黑穗病具有一定的抗性,在抗病育种中可选择利用.     

二十个加拿大玉米群体性状表现

以引进的20个加拿大玉米群体为材料,对其主要性状及玉米丝黑穗病抗性进行评价。供试群体在黑龙江省均具有较好的适应性,且生育期较短,属早熟和中早熟类型,可以在早熟玉米育种中利用。其中,群体EP9的产量及各产量构成因子等性状表现较好,可优先利用。20个群体对丝黑穗病抗性差异较大。其中,群体EP7、EP8、EP15、EP23表现为抗病,占供试材料的20％;群体EP1、EP9、EP12、EP16、EP21表现为中抗,占25％;感病群体11个,占55％,但发病率均小于21％,表明供试群体均对玉米丝黑穗病具有一定的抗性,在抗病育种中可选择利用。     

墨西哥血缘玉米自交系淀粉含量与穗部性状灰色关联度分析

本文采用灰色关联度分析方法,分析了来自CIMMYT的Pob45、Pob46、Pob69、Pob70四个改良群体自交系的玉米淀粉含量和穗部性状的关系,得出与淀粉含量关系密切的穗部性状是：穗重＞行粒数＞百粒重＞穗粗＞穗长＞穗行数。玉米淀粉主要存在于胚乳细胞中,而胚乳重量占玉米籽粒90%以上。因此,选择行粒数多、百粒重大的材料有利于得到淀粉含量高的自交系。     

贵州玉米种质资源的抗病性鉴定与评价

对贵州省内保存的550份玉米种质资源进行了大斑病、小斑病、丝黑穗病和矮花叶病抗性鉴定，结果表明：种质资源对玉米主要病害的抗性是丰富的，不同的材料间抗性差异显著。通过鉴定，筛选出抗大斑病种质105份，抗小宽病资源17份，抗丝黑穗病资源151份，抗矮花叶病种质23份，这些抗源有的具有多抗性，抗两种以上病害的种质有47份。筛选出的抗源可提供育种者通过各种技术手段进行利用。应进一步深入研究，加大从地方品种中发掘和改良、创新种质的力度。     

CIMMYT种质对东农250亲本自交系的改良效果研究

本试验将CIMMYT种质Pob46和Pob45分别导入东农250的父本自交系吉846和母本自交系444中,研究CIMMYT种质对其产量及其他农艺性状的改良效果。结果表明吉846改良系和444改良系所配杂交组合的株高及穗位均有所降低,有利于增强组合的抗倒伏性;百粒重普遍增加但产量普遍降低,仅有个别组合增产;其它性状如雄穗一级分支数和行粒数等,二者改良效果有所不同。     

Breeding potential of maize germplasm populations to improve yield and predominant heterotic pattern in Northeast China

Increasing the frequency of favorable alleles in elite germplasm is necessary for germplasm improvement and innovation in maize (Zea mays L.) breeding programs. Jidan27 (Si287 × Si144), an elite commercial single cross hybrid that represents the predominant heterotic pattern Chinese Sipingtou × Stiff Stalk Synthetic, has been widely cultivated in the Northeast China Corn Belt. However, the use of the hybrid Jidan27 has been hampered gradually due to its low yield potential, lack of resistance to lodging, and considerable incidence of head smut disease. Previous studies have evaluated yield potential of exotic populations, but few have considered using these germplasms as donors with favorable alleles to overcome these deficiencies in the hybrid Jidan27. In the present study, 12 exotic populations from CIMMYT and the U.S. and three semi-exotic populations were investigated as sources of favorable alleles to increase yield and lodging resistance, and reducing head smut susceptibility of the hybrid Jidan27. The performance of a set of 30 inbred × populations crosses, the hybrid Jidan27, and the two parental inbred lines Si287 and Si144 was evaluated in three locations for 2 years. Two populations, BS10(FR)C10 and Pop43, were identified as the best donors of favorable alleles lacking in the hybrid for improving the target traits. Further, BS13(S)C7 and Cpop.16 were also found to be better choices for improving grain yield and head smut resistance of the hybrid. These results suggest that the elite exotic germplasms evaluated here could provide useful genetic variability to improve other Chinese Sipingtou × Stiff Stalk Synthetic crosses related to Si287 × Si144 that are widely grown in Northeast China.     

玉米矮花叶病毒抗性资源鉴定的研究

利用人工接毒方法对 70份玉米种质资源进行了两年玉米矮花叶病毒B株系的抗性鉴定。依据病情指数 ( % )将抗病程度分为高抗、抗、中抗及感病 4个等级。试验筛选出高抗自交系 4份、高抗单交种 3个、抗病毒自交系 10份、抗病单交种 3个 ;中抗自交系 6份、中抗群体 3个。讨论了这些种质资源在我国抗玉米矮花叶病遗传及育种研究上的应用价值     

CIMMYT's approach to breeding for wide adaptation

Summary The wheat area in developing countries, including China, is around 100 million ha. To address the needs of these very diverse wheat growing areas, CIMMYT has defined 12 wheat mega-environments (ME). A ME is defined as broad, not necessarily continuous often transcontinental area with similar biotic and abiotic stresses, cropping systems and consumer preferences. The factors describing each ME are presented.CIMMYT's breeding methodology is centered around the development of widely adapted germplasm with high and stable yield across a wide range of environments. Segregating populations are alternating screened in two diverse environments in Mexico. One key requirement is that all germplasm is tested under near optimum conditions for its yield potential. The second one is multi-locational testing of advanced lines at sites that represent a given ME (key locations) and careful screening of germplasm for tolerance to abiotic and biotic stresses specific to that environment. This methodology has permitted the pyramiding of a large number of multiple resistance genes for use against a wide spectrum of diseases and tolerance to abiotic stresses within each ME. In addition, the widespread testing of lines allows the identification of traits which are beneficial in several environments. Data from international nurseries are used to further delineate environments within an ME. This approach has proven to be successful since around 70% of the spring wheat area in developing countries (excluding China) is planted to varieties derived directly or indirectly from CIMMYT germplasm. The performance of the bread wheat cultivar Pastor in international trials is given as an example for a wide adaptation.     

Race non-specific resistance to rust diseases in CIMMYT spring wheats

Rust diseases continue to cause significant losses to wheat production worldwide. Although the life of effective race-specific resistance genes can be prolonged by using gene combinations, an alternative approach is to deploy varieties that posses adult plant resistance (APR) based on combinations of minor, slow rusting genes. When present alone, APR genes do not confer adequate resistance especially under high disease pressure; however, combinations of 4?C5 such genes usually result in ??near-immunity?? or a high level of resistance. Although high diversity for APR occurs for all three rusts in improved germplasm, relatively few genes are characterized in detail. Breeding for APR to leaf rust and stripe rust in CIMMYT spring wheats was initiated in the early 1970s by crossing slow rusting parents that lacked effective race-specific resistance genes to prevalent pathogen populations and selecting plants in segregating populations under high disease pressure in field nurseries. Consequently most of the wheat germplasm distributed worldwide now possesses near-immunity or adequate levels of resistance. Some semidwarf wheats such as Kingbird, Pavon 76, Kiritati and Parula show high levels of APR to stem rust race Ug99 and its derivatives based on the Sr2-complex, or a combination of Sr2 with other uncharacterized slow rusting genes. These parents are being utilized in our crossing program and a Mexico-Kenya shuttle breeding scheme is used for selecting resistance to Ug99. High frequencies of lines with near-immunity to moderate levels of resistance are now emerging from these activities. After further yield trials and quality assessments these lines will be distributed internationally through the CIMMYT nursery system.     

抗丝黑穗病、抗败育高粱A_2细胞质雄性不育系A_2Sx3197的选育

A1Tx3197曾经是我国广泛应用的高粱细胞质雄性不育系,20世纪70年代末,由于高粱丝黑穗病病菌生理小种分化,该不育系以及用其配制的杂交种逐渐失去了对高粱丝黑穗病菌的抗性。同时该不育系小花败育日渐严重,制种产量极低,甚至造成绝收。为了改良A1Tx3197的抗病性及抗败育性,本研究利用A2保持系在A1位点含有A1育性恢复基因MS1MS1和在A1细胞质背景下表现恢复的特点,以不育系A1Tx3197为轮回亲本,以含有抗丝黑穗病、抗败育基因的BV4为供体,通过杂交和多代回交,得到含有双抗基因的A2类型细胞质雄性不育的保持系BSx3197(MS1ms1ms2ms2),在该材料自交的同时,用其对A2细胞质雄性不育系进行细胞核代换,经过多代回交和自交,最终育成了抗丝黑穗病、抗败育的A2细胞质雄性不育系A2Sx3197和保持系BSx3197(MS1MS1ms2ms2)。结果表明,新选育的不育系A2Sx3197在A1和A5细胞质背景下表现恢复,在A2、A3、A4、A6和9E细胞质背景下表现不育,丝黑穗平均发病率为0～0.8%,败育率为0～8.4%,抗丝黑穗病性、抗败育性明显优于被改良不育系,接近或达到抗源供体BV4水平;而在抽穗期、株高、穗长、穗宽、千粒重、穗粒重、粒色、壳色、穗形、穗型等主要性状方面与A1Tx3197差异不显著。