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1.
An essential assumption underlying markerbased prediction of hybrid performance is a strong linear correlation between molecular marker heterozygosity and hybrid performance or heterosis. This study was intended to investigate the extent of the correlations between molecular marker heterozygosity and hybrid performance in crosses involving two sets of rice materials, 9 indica and 11 japonica varieties. These materials represent a broad spectrum of the cultivated rice gene pool including landraces, primitive cultivars, historically important cultivars, modern elite cultivars and parents of superior hybrids. Varieties within each set were intermated in all possible nonreciprocal pairs resulting in 36 crosses in the indica set and 55 in the japonica set. The F1s and their parents, 111 entries in total, were examined for performance of seven traits in a replicated field trial. The parents were surveyed for polymorphisms using 96 RFLP and ten SSR markers selected at regular intervals from a published molecular marker linkage map. Molecular marker genotypes of the F1 hybrids were deduced from the parental genotypes. The analysis showed that, with very few exceptions, correlations in the indica dataset were higher than in that of their japonica counterparts. Among the seven traits analyzed, plant height showed the highest correlation between heterozygosity and hybrid performance and heteorsis in both indica and japonica datasets. Correlations were low to intermediate between hybrid performance and heterozygosity (both general and specific) in yield and yield component traits in both indica and japonica sets, and also low to intermediate between specific heterozygosity and heterosis in the indica set, whereas very little correlation was detected between heterosis and heterozygosity (either general or specific) in the japonica set. In comparison to the results from our previous studies, we concluded that the relationship between molecular marker heterozygosity and heterosis is variable, depending on the genetic materials used in the study, the diversity of rice germplasms and the complexity of the genetic basis of heterosis.  相似文献
2.
选用分布于水稻(Oryza sativaL.)12条染色体上的25对SSR(Simple sequence repeats)引物,分析了生产中广泛应用的35个杂交 水稻恢复系,在35个杂交水稻恢复系材料间共检测出65个等位基因(alleles),平均每对SSR引物可检测到2.6个等位基因,PIC(Polymorphism index content)值的变动范围为0.206-0.682,平均值为0.414。聚类分析表明,我国杂交 水稻恢复系资源比较丰富,但其遗传差异较小,遗传背景单一,从而在很大程度上限制了我国水稻杂种优势的利用。  相似文献
3.
籼型杂种稻米品质性状的数量遗传分析   总被引:42,自引:1,他引:41  
敖雁  徐辰武  莫惠栋 《遗传学报》2000,27(8):706-712
应用新近提出的p^+q^+pq交配设计的种子性状遗传表达鉴别方法,分析了籼型水稻3个不育系和10个恢复系配组的30个杂种F1植株上的F2种子及其亲本的9个稻米品质性状。结果表明:(1)粒长、粒宽、粒重、糙米率和完整精米率5个性状在F2米粒间没有发生遗传分离,它们的遗传受二倍体母体基因型(F1植株)控制。(2)垩白率、直链淀粉含量、糊化温度和胶稠度4个性状则在F2米粒间有极显著的遗传分离,帮主要受三  相似文献
4.
水稻长穗颈高秆隐性基因eui2的遗传及其微卫星分析   总被引:39,自引:1,他引:38  
从水稻(Oryza sativa L.)协青早B的辐射M2群体中获得以最上节间伸长特征的长穗颈高秆突变系协青早eB-1和协青早eB-2,与原品系协青早B的秆性状相比,协青早eB-2的第一节间长占总秆长的65.3%,其第一节间的增长量占秆长总增长量的90.2%;协青早eB-1的第一节间长占总秆长的54.8%,其第一节间的增长量占秆长总增长量的53.3%,遗传分析表明:协青早eB-2中的长穗颈高秆性状各由一对隐性基因控制,二之间互不等位。与已报道的eui基因的等位性测验表明:协青早eB-2的eui基因与其不等位,为新的长穗颈高秆隐性基因,命名为eui2,协青早eB-1的eui基因则与其等位。微卫生分析表明:eui2基因与第10第染色体的RM258、RM269、RM271和RM304连锁,其遗传距离分别为12.0cM、12.9cM、35.1cM、1.4cM。由此推断,eui2基因位于第10染色体长臂的中部。  相似文献
5.
DNA methylation is known to play an important role in the regulation of gene expression in eukaryotes. In this study, we assessed the extent and pattern of cytosine methylation in the rice genome, using the technique of methylation-sensitive amplified polymorphism (MSAP), which is a modification of the amplified fragment length polymorphism (AFLP) method that makes use of the differential sensitivity of a pair of isoschizomers to cytosine methylation. The tissues assayed included seedlings and flag leaves of an elite rice hybrid, Shanyou 63, and the parental lines Zhenshan 97 and Minghui 63. In all, 1076 fragments, each representing a recognition site cleaved by either or both of the isoschizomers, were amplified using 16 pairs of selective primers. A total of 195 sites were found to be methylated at cytosines in one or both parents, and the two parents showed approximately the same overall degree of methylation (16.3%), as revealed by the incidence of differential digestion by the isoschizomers. Four classes of patterns were identified in a comparative assay of cytosine methylation in the parents and hybrid; increased methylation was detected in the hybrid compared to the parents at some of the recognition sites, while decreased methylation in the hybrid was detected at other sites. A small proportion of the sites was found to be differentially methylated in seedlings and flag leaves; DNA from young seedlings was methylated to a greater extent than that from flag leaves. Almost all of the methylation patterns detected by MSAP could be confirmed by Southern analysis using the isolated amplified fragments as probes. The results clearly demonstrate that the MSAP technique is highly efficient for large-scale detection of cytosine methylation in the rice genome. We believe that the technique can be adapted for use in other plant species. Received: 23 October 1998 / Accepted: 11 January 1999  相似文献
6.
用微卫星DNA标记检测中国主要杂交水稻亲本的遗传差异   总被引:35,自引:0,他引:35  
选用分布于水稻(OryzasativaL.)12条染色体上的20对SSR(Simplesequencerepeats)引物,分析了具有多种质源和较大应用面积的24个水稻胞质雄性不育系、1个光(温)敏核不育系、3个保持系和5个生产中应用较广的恢复系。在以上33份杂交水稻亲本材料间共检测出102个等位基因(alleles),平均每对SSR引物可检测到5.1个等位基因。PIC(polymorphicindexcontent)值的变动范围为0.274~0.773,平均PIC值为0.554。从56对SSR引物中筛选出5对引物,能够有效地区分所有供试的水稻雄性不育系和恢复系。杂交水稻亲本的聚类分析表明:(1)我国水稻雄性不育系遗传变异丰富,但生产中主要应用的水稻雄性不育系遗传背景比较单一。(2)生产中应用面积较大的水稻雄性不育系遗传变异较恢复系差。(3)生产中主要应用的水稻雄性不育系与恢复系分别聚类于不同的类群,且遗传关系较远。  相似文献
7.
杂交稻及其三系叶片衰老过程中SOD、CAT活性和MDA含量的变化   总被引:30,自引:2,他引:28  
对杂交水稻及其三系主茎第11叶叶片自然衰老过程中超氧物歧化酶(SOD)、过氧化氢酶(CAT)和丙二醛(MDA)含量的变化进行了研究,结果表明:叶片衰老过程中,SOD和CAT活性下降,MDA的含量增加,可作为衰老特征的叶绿素和可溶性蛋白质含量明显下降;SOD的活性和MDA的含量变化相对应;CAT活性大幅度下降与SOD之间的不平衡,致使O_2~-代谢中间产物累积而引起膜的损伤。不育系的衰老进程比杂交水稻、恢复系和保持系慢,其SOD和CAT活性明显高于其它三者,可能是不育系不易早衰的原因之一。  相似文献
8.
野败型杂交水稻恢复基因的AFLP标记研究   总被引:29,自引:3,他引:26  
选择汕优63F2的高可育株和高不育株分别建立2个基因池,利用AFLP标记技术对2池间的多态性进行了研究,分析表明,64组引物在两池间全部扩增出了稳定,清晰的带纹,共计3477条带。多数引物在基因池间未呈现多态性,只有引物组合E-AGC/M-CAA在基因池间表现多态,用双亲、F1、F2单株以及生产和育种上的骨干不育系与恢复系验证均表明这组引物所揭示的多态性片段与恢复基因有关(命名为AP1)。AP1为  相似文献
9.
 较为系统地研究了两个超高产杂交稻‘两优培九’、‘华安3号’和多年来大面积推广的常规杂交稻‘汕优63’不同生育期的光合色素含量、净光合速率和水分利用效率。结果表明,在苗期,3个杂交稻的单位叶面积的叶绿素(Chl)含量差别不大,类胡萝卜素(Car)的含量以‘汕优63’为最高。然而,随着发育阶段的推进,到分蘖期,尤其是抽穗期剑叶的单位叶面积Chl和Car含量,两个超高产杂交稻高于‘汕优63’。从苗期到抽穗期,超高产杂交稻‘两优培九’和‘华安3号’的净光合速率(Pn)都比‘汕优63’高,而在苗期的午间强光条件下和分蘖期的早晨以及抽穗期的早晚相对弱光条件下其Pn的差别尤为显著。在苗期,‘汕优63’的水分利用效率(WUE)略高于‘两优培九’和‘华安3号’;到分蘖期和抽穗期,在上午10时之前和下午14时以后的时间段,则是两个超高产杂交稻明显高于‘汕优63’。这些结果说明,超高产杂交稻‘两优培九’和‘华安3号’不仅有较高的Pn和较强的抗光抑制能力,而且还能充分利用早晨和傍晚较弱的光强进行光合作用,这些是它们之所以高产的重要生理基础。此外,超高产杂交稻在生长发育的中后期(分蘖期和抽穗期)具有较高的WUE,有利于节约农业用水。  相似文献
10.
利用SSR标记定位明恢63的2对恢复基因   总被引:27,自引:0,他引:27  
选取珍汕97A和明恢63杂交组合的F2高可育和高不育单株构建基因池,利用302对SSR引物对其进行了多态性分析。结果表明,位于第1染色体上的RM1和位于第10染色体上的RM258,RM304在亲本,基因池间表现多态性,用F2单株验证证明它们与野败型恢复基因连锁,完全不育株分析表明,与恢复基因间的遗传距离分别为1.9,2.9和0.0cM,野败型,红莲型,BT型3种不育胞质恢复基因在第10染色体上可能为同一基因或家族成员。  相似文献
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