水稻雄性不育突变体gamyb5的鉴定与基因定位

在⁶⁰Co-γ射线辐射诱变籼稻中恢8015的突变体库内发现了一个无花粉型雄性不育突变体gamyb5。gamyb5 的株型、株高、分蘖数等农艺性状与野生型中恢8015无差异,而其花药细长且呈白色半透明状,花药中无花粉粒。花药半薄切片观察结果表明,gamyb5的小孢子母细胞减数分裂异常,没有形成正常的四分体和小孢子,并且绒毡层异常伸长,细胞程序性死亡延迟。对以gamyb5 为母本,与野生型中恢8015 和广亲和粳稻品种02428分别配制的杂交组合遗传分析表明,gamyb5 突变性状受一个隐性核基因控制。利用gamyb5 和02428 杂交的F₂定位群体,最终将突变基因精细定位于第1染色体长臂的ZF-29和ZF-31两个标记之间,物理距离约16.9 kb。对该区域内2个完整的开放阅读框测序分析发现,编码受赤霉素诱导的MYB转录因子基因LOC_Os01g0812000的第2外显子存在8个碱基的缺失,导致翻译提前终止。qRT-PCR检测到影响花药发育的调控因子UDT1、TDR、CYP703A3和CYP704B2的表达量在突变体中比野生型中极显著降低。进一步证明GAMYB在花药减数分裂和绒毡层细胞程序性死亡过程中起关键作用。     

Association Mapping and Marker Development of Genes for Starch Lysophospholipid Synthesis in Rice

Phospholipids are a major kind of lipids in rice grains and have fundamental nutritional and functional benefits to the plant. Their lyso forms(lysophospholipids, LPLs) often form inclusion complexes with amylose or independently influence the physicochemical and functional properties of rice starch. However, the genetic basis for LPL synthesis in rice endosperm is largely unknown. Here, we performed a preliminary association test of 13 LPL compositions among 20 rice accessions, and identified 22 putative main-effect quantitative trait loci responsible for all LPLs except for LPC14:0 and LPE14:0. Five derived cleaved amplified polymorphic sequences and one insertion/deletion marker for three LPL-synthesis-related candidate genes were developed. Association analysis revealed two markers significantly associated with starch LPL traits. These results provide an insight into the genetic basis of phospholipid biosynthesis in rice and may contribute to the rice quality breeding programs using functional markers.     

苹果遗传图谱的构建与QTL定位研究进展

对近年来构建的苹果遗传连锁图谱和相关重要性状的QTL定位研究进展进行了总结分析,主要包括苹果单一群体遗传连锁图谱、多个群体遗传连锁图谱、物理图谱的构建,以及抗病性状和主要农艺性状的QTLs定位,并讨论了相关研究中目前存在的问题及对遗传连锁图谱后期的展望,为苹果育种者在分子标记辅助育种方面提供参考。     

水稻窄叶突变体nal10的鉴定与基因精细定位

利用EMS诱变粳稻品种武运粳7号获得一个新窄叶突变体nal10,该突变体在苗期表现出极窄叶和弱小的特征,在生殖期表现出矮化、窄叶、畸颖和不育的表型。组织解剖学分析表明,nal10的叶片窄化可能是由于叶片大脉和小脉数量减少造成的。遗传分析表明,该窄叶表型受一对隐性核基因控制。利用nal10与台中本地一号(TN1)构建的F₂群体,通过混合分离法,在第1染色体上找到3个紧密连锁的SSR标记(RM1287、RM562和RM5638)。进一步利用新发展的分子标记,最终将该基因定位在STS标记PK83和PK78之间的55.2 kb范围内,该区间共有8个开放阅读框。RT-PCR分析表明,NAL10的突变能够造成生长素生物合成、信号转导和运输基因转录水平的下降,因此NAL10是一个与生长素相关的窄叶新基因。这些结果为进一步克隆该基因、丰富水稻叶发育的遗传调控网络打下了基础。     

水稻窄卷叶突变体Nrl3(t)的基因定位

利用⁶⁰Co-γ射线辐射诱变籼稻恢复系中恢8015,获得了一份窄卷叶突变体Nrl3(t)。与野生型中恢8015相比,突变体叶片显著变窄内卷、株高降低、穗长变短、结实率降低、千粒重降低、粒长粒宽减小。细胞学分析表明,突变体维管束减少和泡状细胞不够饱满是导致叶片变窄卷曲的原因。遗传分析表明该突变体受一对隐性核基因控制,以窄卷叶突变体Nrl3(t)与粳稻品种02428杂交获得的F₂分离群体作为定位群体,利用SSR标记和新开发的InDel标记,将窄卷叶基因Nrl3(t)定位于第2染色体长臂标记C9和C10E之间约70.3 kb区间内。研究结果为该基因的克隆及进一步揭示水稻窄卷叶形成的分子机理奠定了基础。     

Genetic Analysis and Molecular Mapping of Two SMV-Resistance Traits in Soybean： Adult-Plant Resistance and Resistance to Seed Coat Mottling

Soybean mosaic virus （SMV） could lead to adult-plant system diseases, and cause mottling of soybean seeds. Genetic analysis and molecular mapping were conducted using an F2 population and derived F3 families from two crosses of Dongnong 3C624 （susceptible）x Dongnong 8143 （resistant） and Dongnong 3C628 （susceptible）× Tie 6915 （resistant）. Simple sequence repeat （SSR） markers with bulked segregation analysis （BSA） were used to conduct genetic mapping of the resistance to SMV1 in the segregating populations. The results indicated that resistance to SMV1 in adultplants and the resistance to seed coat mottling in Dongnong 8143 and Tie 6915 was separately controlled by one single dominant gene. The two dominant genes were identified to be linked on the MLG F by Mendel＇s genetics and SSR genetic mapping. The order and distance of markers DPRSMV1 and DSRSMV1 were Sat 229-6.9 cM-DSRSMV1-4.6 cM-Sat_317-3.6 cM-DPRSMV1-5.2 cM-Satt335. The order and distance of markers TPRSMV1 and TSRSMV1 was Satt160-16.1 cM-TPRSMV1-7.3 cM-Satt516-2.0 cM-TSRSMV1-4.5 cM-Sat_133. This research provides the useful information for breeders to select the two types of SMV resistance simultaneously in soybean breeding through molecular marker-assisted selection （MAS）.     

Quantitative Trait Loci for Resistance Against Fusarium Wilt Based on Three Cotton F2 Populations

Fusarium wilt （FW） is one of the most common cotton diseases in the world. Identification of QTLs conferring resistance to FW is key for the incorporation of resistance genes into elite cultivars. Two intraspecific （cross between Gossypium hirsuturn L.） and one interspecific （cross between Gossypium hirsutum L. and Gossypium bardence L.） F2 populations were constructed by using a highly resistant cultivar and crossing it to a susceptible cultivar with 154, 79, and 148 offsprings, respectively. Simple sequence repeats （SSR） were used to screen genomic regions closely linked to FW resistance. The results showed that five QTLs associated with FW resistance were detected in two intraspecific populations using a composite interval mapping method under four different conditions. Four of these loci located on Chr. 2/Chr. 17 neighboring markers JESPR304 or CIR305 which explained 13.1 to 45.9% of the phenotypic effect. Furthermore, JESPR304 and CIR305 were previously testified and found to be tightly linked. It is possible that these four QTLs detected under different conditions were the same resistance QTL/gene. We consider that there is the possibility of a major FW resistant gene in intraspecific populations. In the interspecific mapping populations two QTLs were detected on Chr. 9 and Chr. 12/26 which explained great phenotypic variance of 49.4 and 45.7%. As the location of QTLs for FW resistance among the intraspecific and the interspecfic populations were totally different, it is suggested that there may be different resistance mechanisms between G. bardence L. and G. hursutum L. Thus, the present research provides an opportunity to understand the genetic control of resistance to FW in Gossypium hirsutum and Gossypium bardence and to conduct MAS in breeding programs to develop FW resistant cultivars.     

水稻紫色性状的遗传分析和基因定位

本文综述了水稻紫色性状的遗传分析、紫色基因定位研究方面取得的进展,并对此类相关工作进行了展望。     

稻谷耐储藏性的研究概况

综述了水稻耐储藏特性研究评价体系、机理及基因定位等方面的研究进展,以期为水稻耐储藏性研究提供参考。     

陆地棉极短纤维突变体基因Li_2的遗传与定位

Li2突变体是在纤维伸长发育阶段纤维极端缩短类型的突变体,其控制极短纤维表型的基因被命名为Li2。本文以(Li2×海7124)F2及(Li2×sub18)F2作为标记群体,结合本实验室最新的海陆种间分子遗传图谱上染色体18的标记信息,对陆地棉纤维突变体Li2的极短纤维性状进行基因定位。在(Li2×海7124)F2分离群体中,纤维性状分离比符合孟德尔3∶1的分离,证明Li2突变体的极短纤维性状是由一对完全显性单基因控制。而在(Li2×sub18)F2分离群体中,纤维性状分离比出现异常,不符合3∶1的分离比,这可能与Li2突变体的温敏特性有关。利用JoinMap 3.0连锁分析软件,使用含623个单株的(Li2×海7124)F2群体将Li2基因定位在18染色体的端部,与最近标记Z08的遗传距离为6.051 cM;使用含651个单株的(Li2×sub18)F2群体将Li2基因也定位在了18染色体的端部,与最近标记Z08的遗传距离为9.266 cM。研究结果为进一步精细定位与图位克隆该基因提供了基础。