共查询到19条相似文献,搜索用时 647 毫秒
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选择及未选择的依阿华坚秆玉米群体的群体平均数及遗传方差J.F.HolthausK.R.Lamkey轮回选择是一种广泛用于玉米育种的循环育种方法,它能增加玉米种质资源。通过轮回选择法群体改良可达到两个目标:通过增加有利等位基因的频率,提高群体的平均性状... 相似文献
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干旱条件下玉米产量的主要相关性状研究 总被引:2,自引:0,他引:2
本文研究了在干旱条件下玉米产量的主要相关性状.结果表明,在干旱条件下,玉米产量主要与果穗性状即千粒重、穗长、穗粗有正相关,与株高也有正相关,但产量与出苗至吐丝日数为负相关.据此,作者提出了玉米杂交种抗旱的3个指标,与国际玉米小麦改良中心1994年提出的玉米5个抗旱指标一道构成了较完善的玉米抗旱指标体系。 相似文献
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玉米对干旱的反应取决于新陈代谢能力、形态结构和生育阶段.开花期逢遇干旱使玉米产量下降幅度最大.随着产量下降,环境方差所占比例增大,遗传力降低,直接选择效率不高.在干旱条件下,寻找遗传力高且与产量高度相关的第二类性状,构建选择指标,可提高耐旱选择效率.雌雄开花间隔天数(ASI)和单株穗数是可供利用的第二类性状,对其选择所获得的产量增益,在干旱和正常水分条件下均可表现出来.耐旱育种目的在于改变基因型对干旱环境的反应,实现耐旱丰产目标.根据目标环境特征,设计适宜的耐旱选择程序,结合分子标记辅助选择技术,鉴定和利用现有优良耐旱种质和CIMMYT耐旱群体,是我国进行耐旱育种和种质改良的可选途径。 相似文献
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在年降雨量不足40mm的敦煌市,设干旱胁迫和正常灌水两个处理进行试验研究,考察与抗旱性相关的产量性状,采用抗旱指数的方法,从生态抗旱的角度进行抗旱性鉴定,探索野生大豆的抗旱潜力,拓宽大豆抗旱育种基因资源。应用产量性状指标评定野生大豆品种的抗旱性,简单、易行、可靠性高,尤其在进行野生大豆品种资源抗旱鉴定筛选过程中更显示出它的优越性。 相似文献
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干旱是包括中国在内的世界上大多数玉米生产国家的重要农业灾害之一,解决干旱问题的有效途径包括培育抗旱型和节水型的玉米杂交种.多年来,通过常规手段进行玉米抗旱育种取得了一定进展,但由于多方面原因,其育种效率没有得到进一步提高.而与此同时,对玉米在干旱胁迫下的生理生化途径研究很多,其成果可以为抗旱育种提供理论指导;尤其是近年来应用分子标记技术和基因组学技术对玉米抗旱性进行了深入的遗传剖析,其研究结果也为玉米抗旱分子育种提供了新的手段和思路.同时评述了相关研究领域的进展,并讨论今后的发展趋势。 相似文献
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玉米抗旱性指标研究进展 总被引:1,自引:0,他引:1
干旱作为玉米生长发育最主要的非生物逆境因子,已成为限制玉米产量形成的关键生态因素,也是我国玉米产量产生波动的重要原因,对粮食生产安全构成严重威胁。玉米抗旱性是水分胁迫条件下表现出的一种复杂综合特性,其适应干旱的形态结构是长期进化的结果,其生理指标变化也是一系列适应性改变后的综合表现。当今水资源短缺日益成为突出问题,且对玉米造成干旱的外部因素较多。本文从鉴定方法、形态指标、生理生化等方面阐述玉米抗旱机制与鉴定方法,综述玉米抗旱性最新研究进展。发展抗旱性玉米研究,为创制选育新的耐旱种质提供支撑,最终提升玉米抵御干旱胁迫的能力,这对于保障玉米可持续生产、解决粮食安全具有重要意义。 相似文献
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Yanli Lu Zhuanfang HaoChuanxiao Xie Jose CrossaJose-Luis Araus Shibin GaoBindiganavile S. Vivek Cosmos MagorokoshoStephen Mugo Dan MakumbiSuketoshi Taba Guangtang PanXinhai Li Tingzhao RongShihuang Zhang Yunbi Xu 《Field Crops Research》2011,124(1):37-45
A total of 550 maize inbred lines collected from global breeding programs were evaluated for drought resistance under both well-watered and water-stressed environments. The evaluation was based on multiple measurements of biomass taken before and after the drought stress was applied using the normalized difference vegetation index (NDVI), along with other selection criteria including anthesis-silking interval, leaf senescence, chlorophyll content, root capacitance, final grain yield, and grain yield components. Kernel weight was the most stable trait under drought stress. Correlations between the primary trait (grain yield) and the secondary traits, except the root capacitance and ASI under water-stressed condition, were all significant. Root capacitance had relatively low heritability and low genetic correlation with other drought resistance criteria, and is not recommended as a drought resistance criterion. Significant reduction of NDVI values measured in the afternoon when the leaves became rolling, compared to those measured in the morning when the leaves were open, provides a reliable index for leaf rolling, which however was not significantly correlated with grain yield. NDVIs measured across different developmental stages were highly correlated with each other and with most of the secondary traits as well as, grain yield, indicating that NDVI can be used as a secondary trait for large-scale drought resistance screening. Regression models built based on non-yield drought criteria and yield components explained about 40% and 95% of the variation for the grain yield, respectively. Some maize lines developed in China for temperate regions showed strong drought resistance comparable to tropical maize lines when tested under tropical condition, indicating that temperate lines with a wide adaptability can be used in drought resistance breeding for both temperate and tropical environments. 相似文献
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Maize drought tolerance: Potential improvements through arbuscular mycorrhizal symbiosis? 总被引:1,自引:0,他引:1
Due to long-term trends in global climate change and the expansion of maize production in drought-prone regions, the development of drought-tolerant maize varieties is of high importance, particularly for maize producers in developing nations where plant breeding improvements are more easily adopted than high-input agronomic practices. Prior advances in breeding for drought-tolerant maize have often involved selection for beneficial morpho-physiological traits such as a reduced anthesis-silking interval (ASI) and an improved harvest index (HI). Although maize is an effective host of arbuscular mycorrhizae (AM) in infertile and drought conditions, few maize breeding and physiological research programs have examined the potential of AM symbiosis to improve maize drought tolerance. The objective of this review is to highlight the morpho-physiological responses and potential mechanisms through which AM colonization might improve maize drought tolerance and, in doing so, to examine the potential of this symbiotic relationship to serve as an effective tool for improving cultivar drought tolerance. In this review, we briefly describe the general effects of AM symbiosis on plant water relations, and then extensively examine the effects of AM colonization on pre-flowering, flowering, and post-flowering maize morpho-physiology under drought-stress conditions in greenhouse and field settings. We then suggest potential areas for future research related to (a) the adoption of cropping practices promoting AM colonization and survival; (b) the further understanding of AM effects on maize morpho-physiology; and (c) the creation of AM-colonized, drought-tolerant maize cultivars through conventional breeding as well as molecular and genomic techniques. We conclude by discussing practical considerations associated with the use of AM for maize drought-stress research and large-scale, commercial maize production. 相似文献
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黄早四种群自交系在山东省玉米育种和生产中的利用 总被引:1,自引:0,他引:1
黄早四种群自交系(黄早四及其衍生系)是我国玉米育种的五大骨干杂种优势类群之一,建立在黄早四及其改良的衍生系(黄改系)基础之上,具有配合力高、株型好、耐旱耐瘠、适应性广等特点。统计分析山东省审(认)定的165个品种亲本遗传组成,有78个品种具有黄早四种群种质,占审定总数的47.3%。针对黄早四种群自交系及其组配的杂交种耐旱、质优、耐密、高产等特性,探讨在山东省玉米育种和生产上进一步应用的发展前景,提出山东省利用黄早四群种质的改良策略。 相似文献
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我国常用玉米自交系的耐旱性评价 总被引:5,自引:2,他引:3
2007年冬季和2008年春季分别在海南三亚和新疆乌鲁木齐对196份玉米自交系采用两种不同干旱胁迫处理,依据形态性状及产量相关性状评价其耐旱性。通过典型相关分析发现,株高、雌雄开花间隔天数(ASI)、单穗粒重和结实株数百分率4个性状可以作为玉米自交系耐旱性评价指标。采用因子分析方法,计算株高、雌雄开花间隔天数、单穗粒重和结实株数百分率4个性状的综合耐旱系数,对196份玉米自交系进行耐旱性评价,将试验材料分为耐旱、中度耐旱、中度干旱敏感和干旱敏感4种类型。两点试验耐旱级别完全一致的材料有58份,其中耐旱自交系有7份(H201、Mo113、英64、H21、早49、丹598、吉842);中度耐旱自交系有14份(丹黄02、8902、中106、郑22、中黄68、K22等),这些材料为耐旱育种提供了种质基础。 相似文献
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我国玉米杂交种耐旱性评价与分析 总被引:4,自引:0,他引:4
以我国目前生产应用的玉米杂交种为材料,在干旱处理和浇水(对照)条件下,根据成熟期产量和产量构成因素的耐旱指数分析其耐旱性。以耐旱指数为依据将供试材料分为高、中、低3种抗旱类型,表现高抗旱的材料有成单30、川单21、川单25、川单27、丹玉39、登海9、高农901、冀玉9、晋单42、农大108、强盛31、先玉335、新丹2100和豫玉26;表现中抗旱的材料有东德9号、吉单209、浚单20、蠡玉16、临奥1号、鲁单9002、鲁玉13、农大3138、强盛5、铁单10、秀青73-1和中单2号。不同材料的耐旱性表现不同,不同性状的耐旱性也表现不同,说明玉米耐旱性改良具有较大潜力。 相似文献