缺水条件下玉米籽粒产量和抗旱系数的遗传分析

采用灌水与不灌水处理方法对不同玉米自交系和杂交组合的籽粒产量和抗旱系数的遗传分析结果表明：单株籽粒产量在灌水条件下加性效应作用较大，随着水分胁迫程度的增加，加性效应作用相对越来越小，抗旱自交系在缺水条件下的一般配合力效应与灌水条件相比有所提高，而不抗旱自交系有所下降；抗旱系数表现为抗旱自交系的一般配合力效应高，不抗旱自交系的一般配合力效应低，而且随着水分胁迫程度的增加，其加性效应作用愈来愈大，严重水分胁迫条件下抗旱系数的遗传主要受加性效应控制，狭义遗传力较高。     

水分严重胁迫对玉米不同基因型的影响

水分严重胁迫对不同基因型玉米的影响研究结果表明：供试自交系的抗旱性存在着显著的基因型差异；水分胁迫对植株的产量性状、形态发育指标及生理性状都会产生影响，其影响程度随基因型的不同而异，以单株籽粒产量对水分亏缺的反应最为敏感，抗旱自交系具有较强的生理协调性，而不抗旱自交系的这种协调性表现较差。     

宁夏水稻抗旱性研究及综合评价

利用49份宁夏水稻材料,设水分胁迫、非水分胁迫2种处理,调查测定植株的形态性状、生理性状、产量性状及单株产量,通过水分胁迫、非水分胁迫条件下各相对性状对抗旱指数分别进行相关、灰色关联、逐步回归、通径分析。研究结果表明,单株分蘖数、株高、着粒密度、单株有效穗数、单穗实粒数等5个性状与抗旱性显著相关,可作为宁夏水稻抗旱性的鉴定指标。利用模糊隶属函数法对抗旱系数、抗旱指数、综合抗旱能力值进行抗旱性定性分级评价,结果表明,通过筛选得到的5个抗旱鉴定性状进行水稻的综合抗旱能力评价是可行的,综合评价出49份材料中有5份材料抗旱性较强、有6份材料抗旱性次之,综合抗旱能力、抗旱指数是宁夏水稻品种较为合适的抗旱性评价方法。     

晋北区地方油菜品种苗期抗旱性比较

通过了解不同芥菜型春油菜地方品种抗旱性的强弱,挖掘、保护地方抗旱种质资源。试验设置2个干旱胁迫和正常水分3个处理,考察与抗旱性相关的13个指标的变化规律。结果表明,不同地方品种、不同性状对干旱胁迫反应表现程度各异。随着干旱胁迫时间的持续,株高、叶绿素、脯氨酸含量、根系总体积这4个指标重度和中度干旱胁迫的抗旱系数都表现先升后降;净光合速率和水分利用效率的抗旱系数一直减小;蒸腾速率和根系平均直径的重度干旱胁迫的抗旱系数一直缓慢降低,中度干旱胁迫的抗旱系数在胁迫前期有所升高,后期明显降低;根尖数和总根长的抗旱系数都表现先升后降继而平稳;重度和中度干旱胁迫下广灵油菜叶面积和干质量的抗旱系数一直保持最高;重度干旱胁迫下广灵油菜根系总体积表现最高,其余品种基本保持一致。通过抗旱系数和隶属函数法对其抗旱性进行综合评价得出,广灵油菜和天镇黄芥属于中抗旱型,灵丘芥和阳高大芥属于弱抗旱型,适宜在晋北地区推广种植。     

28份玉米自交系抗旱性鉴定

【目的】鉴定28份玉米自交系进行抗旱性,为广西抗旱玉米种质创新和抗旱玉米品种选育提供依据。【方法】在正常灌水和干旱胁迫处理下,测定穗长、穗粗、穗行数、行粒数和百粒重等果穗性状指标,同时测定产量指标。采用隶属函数法对果穗性状指标抗旱系数计算D值,采用产量指标计算抗旱指数,综合评价不同玉米自交系的抗旱性。【结果】D值0.318 6~0.985 7,其中抗旱性强的自交系12份,抗旱性中等的10份,抗旱性弱的6份;产量抗旱指数在0.387 7~1.458 3,其中为抗旱性强的自交系7份,抗旱性中等的10份,抗旱性弱的11份;2种评价结果之间相关性为0.7402,达到极显著正相关。【结论】产量抗旱指数与隶属函数法均可用于玉米自交系抗旱性评价,2方面评价结果均属于抗旱性强的自交系为D1101、Q901、VN、桂39722、YD2、D1113和SP221。     

玉米自交系主要农艺性状与产量和抗旱性的关系研究

对288份玉米自交系进行大田开花期干旱胁迫处理,研究了玉米自交系的产量和抗旱性与水旱两种不同条件下的农艺性状之间的关系.结果表明,干旱胁迫条件下玉米自交系的产量与其在正常灌水条件下的产量性状高度正相关,而与正常灌水条件下的株高和穗位高等性状呈高度负相关;穗粒数多的自交系比穗粒数少的自交系在干旱条件下更高产也更抗旱;穗粒数、株穗数和株高这3个性状与旱地玉米高产抗旱的关系最为密切.     

干旱胁迫对油菜蕾薹期生理特性及农艺性状的影响

【目的】针对长江流域特别是长江上游近几年春季降水偏少易导致干旱的特点,研究水分胁迫对油菜蕾薹期生理特性及农艺性状的影响,为揭示油菜蕾薹期抗旱机制及抗旱品种选育提供理论依据。【方法】采用盆栽的方式,在遮雨网室对两种抗旱性不同的油菜品种中双10号（抗旱性弱）和94005（抗旱性强）蕾薹期进行干旱胁迫,以各性状的抗旱系数研究油菜相关生理指标及农艺性状的变化,在此基础上筛选出适用于该区域油菜蕾薹期抗旱性鉴定的指标。【结果】随着干旱时间的延长,两种油菜的叶片净光合速率、气孔导度、蒸腾速率、胞间二氧化碳浓度、RWC、叶绿素含量、RuBP羧化酶活性、株高、茎粗、一次分枝数以及单株产量抗旱系数均呈下降趋势,下降幅度与胁迫时间成正相关。其中,气孔导度、蒸腾速率抗旱系数下降幅度与材料抗旱性成正相关,其余指标则与材料抗旱性成负相关。抗旱性弱的材料气孔限制值、水分利用率抗旱系数分别呈现出上升-下降与一直下降的趋势,抗旱性强的材料则均为上升趋势。POD、SOD、CAT活性、可溶性糖以及可溶性蛋白相对值随着干旱胁迫时间的延长先升高后下降,抗旱性强的材料增加幅度高于抗旱性弱的材料;细胞膜透性、丙二醛（MDA）含量和脯氨酸相对值随干旱胁迫时间的延长呈上升趋势。对干旱胁迫下的油菜蕾薹期和复水后的成熟期相关指标之间的关系进行分析表明,干旱胁迫下,产量与净光合速率、RWC、叶绿素含量和一次分枝数抗旱系数呈极显著正相关,与细胞膜透性、MDA含量抗旱系数呈显著负相关。主成分分析将单株产量、净光合速率、胞间二氧化碳浓度、气孔限制值、水分利用率、RWC、叶绿素、RuBP羧化酶、SOD、POD、CAT、细胞膜透性、MDA、可溶性糖、株高、茎粗及一次分枝数划分为第一主成分;将叶片气孔导度、蒸腾速率、脯氨酸、可溶性蛋白划分为第二主成分。【结论】第一主成分的各指标（单株产量、净光合速率、胞间二氧化碳浓度、气孔限制值、水分利用率、RWC、叶绿素、RuBP羧化酶、SOD、POD、CAT、细胞膜透性、MDA、可溶性糖、株高、茎粗及一次分枝数）变化与品种抗旱性密切相关,在油菜抗旱品种选育时可作为油菜蕾薹期抗旱性鉴定的主要指标,第二主成分的各指标（叶片气孔导度、蒸腾速率、脯氨酸、可溶性蛋白）则是次要鉴选指标。     

玉米自交铁0941的选育及配合力分析

采用Griffing的完全双列杂交模式4设计,对铁0941的一般配合力和特殊配合力进行分析。经配合力测定和性状鉴定表明:铁0941自交系一般配合力效应值7个性状均为正值,多数性状的一般配合力效应值排在前列,说明铁0941自交系一般配合力高;从综合组合表现看出,在单株产量、百粒重、穗行数、行粒数和穗长等性状上的特殊配合力效应值明显高于其他自交系。铁0941综合性状好,秆矮、抗旱、抗倒、稳产性好。因此,铁0941是具有利用价值的优良玉米自交系。     

多叶玉米主要性状杂种优势及配合力分析

以多叶材料的6个自交系为材料,采用不完全双列杂交法配制了15个杂交组合（只包括F1的正交）,分析了多叶玉米主要性状的配合力、平均优势及相关性。结果表明：（1）对6个自交系和杂种一的株型、产量及品质性状进行方差分析,差异极显著,表明多叶玉米是受基因型的遗传基础控制的。（2）一般配合力效应的分析结果表明,同一组合不同性状之间的配合力效应都有差异,自交系Y53在农艺性状、品质性状和产量上都表现出较大的效应,说明其遗传传递性较强;而自交系P175、P19、P85、J7-3和M7的各个效应值大多是负向的,说明由其组配的后代在各个性状上有下降的趋势。（3）对15个组合的主要性状进行相关分析,生物学产量与株高、穗位高与粗纤维含量之间呈极显著的正相关,株高与穗位高、株高与粗纤维含量、穗位高与粗淀粉含量、百粒重和粗淀粉含量之间呈显著的正相关,其余性状的平均优势间的相关系数均不显著。（4）通过配合力分析及杂种优势的研究,从6个核遗传背景不同的多叶玉米自交系中初步筛选出一个高产、优质的组合,即Y53×P175,这个组合对选育青饲、青贮型玉米提供了新的种质。     

水分胁迫对玉米萌芽期和苗期生长的影响

[目的]为了研究水分胁迫对玉米萌芽期和苗期生长的影响。[方法]用PEG高渗溶液模拟干旱条件,以抗旱性不同的玉米自交系为材料,研究了玉米萌芽期和苗期水分胁迫对其生长的影响及生理指标的变化与抗旱性的关系。[结果]各玉米自交系发芽率、叶片鲜干比明显下降,抗旱性强的自交系下降的幅度较小;根冠比、MDA含量和CAT、SOD酶活性均有一定程度升高,抗旱性强的自交系升高的幅度较大。萌芽期发芽率、苗期叶片鲜干比、根冠比、失水率、MDA含量及SOD和CAT酶活性与玉米抗旱性都有明显的相关性,可作为玉米抗旱性的鉴定指标。[结论]该研究为玉米早期抗旱育种提供了参考。     

Screening of Drought Resistance Identification Indexes for Rice (Oryza sativa L.) Cultivars in Ningxia

The morphological characters, physiological characters, yield traits and yield per plant of total 49 rice cultivars from Ningxia were investigated under conditions of water stress and non-water stress so as to determine the relationship between each trait and yield per plant under water stress and the relationship between each relative character and drought resistance coefficient under water stress and non-water stress. The correlation, grey correlation, stepwise regression and path analyses showed that the til er number per plant, plant height, grain density, effective panicle number per plant and grain number per pan-icle, total 5 traits, were significantly correlated with the drought resistance of rice, and they could be used to identify the drought resistance of rice in Ningxia. In addition, the drought resistance of rice was graded qualitatively according to the subordinate function value of corresponding drought resistance coefficient. The results showed that among the 49 rice cultivars from Ningxia, 6 rice cultivars were highly drought resistant, and 9 rice cultivars were moderately drought resistant, suggesting that the evalua-tion method was feasible and effective.     

Screening of Drought Resistance Identification Indexes for Rice(Oryza sativa L.) Cultivars in Ningxia

The morphological characters, physiological characters, yield traits and yield per plant of total 49 rice cultivars from Ningxia were investigated under conditions of water stress and non-water stress so as to determine the relationship between each trait and yield per plant under water stress and the relationship between each relative character and drought resistance coefficient under water stress and non-water stress. The correlation, grey correlation, stepwise regression and path analyses showed that the tiller number per plant, plant height, grain density, effective panicle number per plant and grain number per panicle, total 5 traits, were significantly correlated with the drought resistance of rice, and they could be used to identify the drought resistance of rice in Ningxia. In addition, the drought resistance of rice was graded qualitatively according to the subordinate function value of corresponding drought resistance coefficient. The results showed that among the 49 rice cultivars from Ningxia,6 rice cultivars were highly drought resistant, and 9 rice cultivars were moderately drought resistant, suggesting that the evaluation method was feasible and effective.     

PEG胁迫下玉米自交系苗期抗旱性鉴定及评价

在人工气候室利用水培试验,对17个玉米自交系进行苗期PEG胁迫,测定对照(正常水分)与PEG胁迫处理的叶片相对含水量、叶绿素荧光参数、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性、脯氨酸(Pro)含量及单株干质量,并采用模糊隶属函数和聚类分析方法对17个玉米自交系进行抗旱性评价和分类,以期筛选出苗期抗旱的玉米种质,建立抗旱性评价体系。结果表明,与对照相比,PEG胁迫下,除PSⅡ最大光化学量子产量Fv/Fm外,其他指标均发生显著变化,表现为叶片相对含水量下降,SOD和POD活性、Pro含量增加,单株干质量增加,说明玉米通过增加Pro含量、提高SOD和POD活性来应对干旱胁迫;同时,PEG胁迫下玉米自交系间的所有指标差异总体均达到了显著水平。隶属函数抗旱性评价与聚类分析将郑7024、郑588、L269、吉853归为中抗旱型玉米自交系,其他自交系均归为弱抗旱型玉米自交系。     

Study and evaluation of drought resistance of different genotype maize inbred lines

Using cultivating experiments in fields under drought stress, yields and characteristics in morphology, growth and development of different genotype maize inbred lines were studied systematically. We evaluated and classified the drought resistance of these materials based on the needed indexes, including subordinate function values of drought resistance (SV), drought coefficient (DC) and drought index (DI) of yield by fuzzy function method and cluster analysis. We also analyzed the correlations between parameters and tested values of traits. The effective parameters and indexes of comprehensive evaluation for drought resistance were selected with principal component analysis. The results showed that under drought stress, the yield of maize inbred lines obviously decreased. The anthesis and silking interval (ASI) was prolonged compared with the control, with a smaller leaf area, thinner stalk, shorter and smaller ears, lengthened barren ear tip, a decline in plant height and ear position, reduced grain number per ear and grain weight, which led to a yield decline. Effects of drought treatment on different maize inbred lines were significantly different. 79-1E, Jiao51, Su1-1 and 18599 were found to be highly resistant to drought, while 1125 and 5311 performed the worst. DI and SV were significantly correlated with drought resistance. Our results indicated that DI, SV, yield and leaf area could be used as parameters and indexes to effectively evaluate the drought resistance of maize. Meanwhile, DC, plant height, ASI, grain number per ear or row, ear length and diameter could be taken as auxiliary parameters and indexes. An applied scientific method for the comprehensive evaluation of drought resistance was offered in this paper. __________ Translated from Journal of Maize Science, 2007, 15(5): 6–11 [译自: 玉米科学]     

提前割除父本对杂交水稻制种产量和种子质量的影响

为研究赶粉结束后提前割除父本对杂交水稻制种产量和种子质量的影响,以‘广8优165’和‘宜优673’两个杂交水稻品种的双亲作为试验材料开展了比较试验。研究发现,赶粉结束后提前割除父本可显著提高杂交水稻制种结实率,增加千粒重,提高种子发芽率,降低易裂颖品种的裂颖率,利于在遭遇不利天气时择机抢收和规避机械混杂,可提高杂交水稻制种产量和增加制种效益。研究证明,赶粉结束后提前割除父本可提升种子质量,增产又增收,是值得推广的一项农艺措施。     

116份玉米自交系的抗旱性评价

为科学评价玉米自交系的抗旱能力,以116份自交系为试验材料,设立干旱胁迫和正常灌水两个处理,在成熟期分别调查两处理自交系的株高、穗位、雄穗主轴长度、穗行数、行粒数、百粒重、存活株数、收获穗数及籽粒产量。结果表明,干旱胁迫下所有性状均极显著减小;干旱对籽粒产量造成的影响最大,对存活株数、百粒重的影响较小;9个性状的抗旱指数之间存在显著相关性;从9个抗旱指数中可提取出4个主成分,累计反映了自交系抗旱性86.5%的信息;使用4个主成分构建了综合抗旱性评价指数并以之聚类,可将116个玉米自交系划分为4类：其中,类1包含郑58等35个中等抗旱型自交系,占比30.2%;类2包含昌7-2等42个弱抗旱型自交系,占比36.2%;类3含JC066等28个干旱敏感型自交系,占比24.1%;类4含JC119等11个强抗旱型自交系,占比9.5%。     

我国玉米生产两个年代主要自交系性状的比较研究

本文研究了我国70年代至80年代玉米生产上应用的主要自交系的性状表现,利用6×13不完全双列杂交模式分析了各性状的一般配合力(GCA)。结果表明,8D年代玉米自交系自身的籽粒产量、生物产量、单株叶面积和株型得到了显著改良;其余多数穗粒性状和叶片功能期也有一定的改良效果。与此同对,籽粒产量、生物产量、单株叶面积、茎粗和茎杆强度等性状的GCA显著提高;部分果穗性状GCA有所增加,但雄穗性状GCA降低。这些性状及其GCA的遗传改良进展,对增加现代玉米杂交种的适应性、抗逆性和产量潜力,降低种子生产成本都具有重要作用。分析认为,当前我国玉米自交系遗传改良首先在主攻产量和品质GCA的基础上,应重视根系与茎杆质量增强抗倒性、以及抗病性和结实性等性状的GCA。同时,还应注意自交系自身的结实性、产量、抗病性和根系质量的改良。     

优质蛋白玉米农艺性状的遗传和相关性及其应用的研究

以10个优质蛋白玉米自交系为材料,按NC—Ⅱ设计,研究了10个农艺性状的遗传方差分量。结果表明:一般配合力方差占遗传方差的比重大于60％的性状有穗位高、单株叶数、穗行数、百粒重、穗粒重和产量;其余性状一般配合力方差占遗传方差的比重在48.01—58.99％之间变化。据(?)gca/(?)G和(?)gca/(?)P分析了不同性状选择和利用效果的差异,按从优至劣的顺序排列各性状得:百粒重>穗粒重>穗位高>单株叶数>穗行数>播种至抽丝天数>每株穗数>株高>产量>行粒数。本文还对相关性状的选择进行了讨论。     

Evaluation and Quantitative Inheritance of Several Drought-Relative Traits in Maize

The authors evaluated 57 parental inbred lines of maize hybrids disseminated in Southwest China for drought tolerance under drought-stressed and well-watered conditions. Multiple regression analyses between drought tolerant coefficients of the grain yield per plant and 15 morphological and physiological traits measured from a subset of 12 selected lines, identified traits 1 and 5, which were important for drought tolerance, at the seedling and reproductive stages respectively. Gene effects, combining abilities, and heritabilities of these traits were estimated using generation mean and diallel cross methods. Dominance effect was more important than additive effect for the plant height, anthesis-silking interval （ASI）, root weight, and the grain yield per plant, whereas, they were about equal for the leaf emergence rate. The variances of special combining ability （SCA） were about double that of the general combining ability （GCA） for plant height, ASI and grain yield per plant, although they were about equal for leaf emergence rate and root weight. Narrow sense heritabilities of the five traits for the reproductive stage were not high （12.8-29.6%）, although broad sense heritabilities for plant height, ASI, and grain yield were as high as 70-85%. A segregating population consisting of 183 F2 plants from the cross N87-1 （drought tolerant） × 9526 （susceptible）, was genotyped at 103 SSR loci and the F2：4 families were evaluated under two water regimes. Twelve quantitative trait loci （QTLs） （two for plant height, five for ASI, four for root biomass, and one for grain yield） were identified, most of which had overdominant gene action. Some chromosomal regions, such as those linked to markers umcl051 （bin 4.08）, umc2881 （bin 4.03）, and phi034 （bin 7.02）, had overlapping QTLs.     

新疆干旱条件下不同基因型玉米自交系耐旱性评价

干旱一直是制约我国粮食生产的一个重要因素.新疆是开展玉米耐旱鉴定最理想的地区之一.筛选具有强耐旱能力的玉米种质,培育耐旱玉米新品种已成为今后玉米育种的重要方向.研究采用玉米开花期干旱胁迫法,以经济产量为主要性状,结合株高、穗位高、雄穗长、雌穗长、秃尖长、穗行数、行粒数、穗粒数、千粒重、ASI等形态生育性状,用抗旱性指数(DRI)作为玉米种质资源耐旱性鉴定与评价的主要指标,对24份玉米自交系的耐旱性做了鉴定与评价.鉴定出502、早314L、早17、海014、新自349、新自523、428、JL02等自交系,耐旱等级在3级以上,具有较强耐旱性.