水稻(Oryza sativa L.)磷酸盐转运蛋白编码基因的表达研究

研究揭示了水稻磷酸盐转运蛋白编码基因的表达．低磷处理下，根系与叶片中的PTW-J，转录子迅速表达，处理7d时达到最高表达量．PTW-J mRNA的诱导积累具有元素的专一性，因为在缺氮、缺钾与缺铁情况下此基因不表达．缺磷处理后恢复供磷，PTW-J转录子积累量明显降低．这些结果说明，PTW-J基因表达是对磷素缺乏的早期反应机制．     

Genetic dissection of a thousand-grain weight quantitative trait locus on rice chromosome 1

Thousand-grain weight （TGWT） is an important factor affecting grain yield as well as grain quality in rice. A quantitative trait locus （QTL） qTGWTI-1 for TGWT was detected previously near DNA marker RG532 on the short arm of chromosome 1 in a recombinant inbred line （RIL） population derived from the indlca-indica rice cross Zhengshan97B （ZS97B）/Milyang46 （MY46）. In this study, two residual heterozygous lines （RHLs）, Chl and Ch2, derived from the ZS97B/MY46 RIL F7 population, were used to develop two Fe populations, RIL-1 and RIL-2. The genome of Chl and Ch2 contains a heterozygous region flanked by RM1--RM3746 and RM151--RM243 on the short arm of chromosome 1, respectively, but is homozygous in other regions. Two tightly linked QTLs, Gwl-1 and Gwl-2, with the same additive direction and similar effect on TGWT, were detected in the region of QTL qTGWTI-1 in population RIL-2. No QTL was detected in the population RIL-1. Four individual RHLs from the population RIL-2 carrying heterozygous segments flanked by RM151--RM10404, RM10381--RM243, RM10435--RM259 and RM10398--RM5359, respectively, were chosen to develop four F= populations. Ten maternal homozygotes and 10 paternal homozygotes were selected from each of the four F2 populations derived from the four RHLs. The four sets of near isogenic lines （NILs） were grown for phenotyping of TGWT and delimitation of Gwl-1 and Gw1-2. Results showed that Gwl-1 and Gw1-2 were located in the intervals RM10376--RM 10398 and RM10404--RM 1344 which cover 392.9 and 308.5 kb regions, respectively. The enhancing alleles were from ZS97B at both loci, and no significant interactions were detected. Genetic dissection of Gwl-1 and Gwl-2 has laid a foundation for their cloning and molecular breeding of grain yield and quality in rice.     

Conditional and unconditional mapping of quantitative trait loci underlying plant height and tiller number in rice (Oryza sativa L.)grown at two nitrogen levels

In this study, we used 127 double haploid (DH) lines to analyze agricultural traits of rice. The DH lines, derived from a ZYQ8 (indica)/JX17 (japonica) cross by anther culture, contained 160 RFLP and 83 SSR markers. Unconditional and conditional quantitative trait loci (QTL) mapping was conducted to analyze plant height (PH) and tillers per plant (TP) at ?ve growth stages that were grown at two nitrogen levels. Fourteen PH and 13 TP unconditional QTL were identified in the di?erent growth stages, including 19 QTL from high-nitrogen (HN) and 14 QTL from low-nitrogen (LN) conditions. The conditional QTL for 14 genomic regions under LN/HN conditions showed that there was a significant effect on PH and TP across the different stages. Only one conditional QTL, ph2-3, was unable to be detected in unconditional mapping. More QTL were detected in the ?rst four rice growth stages than in the final stage. Furthermore, a line from the DH mapping population, DH78, was identified in extreme phenotypes of PH and TP that exhibited dwarfism and less-tiller (dft) characters. The gene dft1 was mapped to chromosome 2 using a backcrossed population of DH78/JX17 through a mapbased cloning strategy. The location of dft1 coincided with the mapping region of the small-LOD peak, QTL ph2 and tp2, which were identified in plants grown in low-nitrogen conditions. Further backcrossing and fine-mapping successfully delimited the dft1 locus to a 91 kb region.     

籼粳杂交稻主要农艺性状之间的遗传相关分析

用混合线性模型方法对舢粳亚种间杂交组合农艺性状的相关性进行了遗传研究,结果表明：被测性状之间大都存在一定程度的相关．其中,株高与实粒数、结实率,穗长与总粒数、实粒数,总粒数与实粒数和结实率,以及实粒数与结实率之间具有显著的表型相关,总粒数与实粒数,实粒数与结实率,以及穗长与株高和结实率之间具有显著的遗传相关．进一步的分析表明,性状之间的遗传相关大多归因于显性效应,而粒重与穗长、总粒数和实粒数之间,以及总粒数与实粒数之间还具有极显著的加性相关     

普通野生稻迁地保护种群的数量动态研究

通过对江西东乡濒危植物普通野生稻（Qryzarufipogon）种群在迁移地实施迁地保护,研究并评价了迁地保护后的濒危植物种群动态。结果表明,普遍野生稻种群里迅速增长的趋势,分布面积迅速扩大,通过无性繁殖及有性繁殖实现种群更新,有性繁殖正常,实生苗补充在种群增长中起重要作用;无性繁殖旺盛,对新生境表现出良好的适应性。濒危种迁地保护是成功的,杂草是阻碍濒危植物种群增长的主要原因,水位控制是生境管理的重要手段。     

Efficient indica and japonica rice identification based on the InDel molecular method: Its implication in rice breeding and evolutionary research

An efficient molecular method for the accurate and efficient identification of indica and japonica rice was created based on the poly-morphisms of insertion/deletion (InDel) DNA fragments obtained from the basic local alignment search tool (BLAST) to the entire genomic sequences of indica (93-11) and japonica rice (Nipponbare). The 45 InDel loci were validated experimentally by the polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis (PAGE) in 44 typical indica and japonica rice varieties, including 93-11 and Nipponbare. A neutrality test of the data matrix generated from electrophoretic banding patterns of various InDel loci indicated that 34 InDel loci were strongly associated with the differentiation of indica and japonica rice. More extensive analyses involving cultivated rice varieties from 11 Asian countries, and 12 wild Oryza species with various origins confirmed that indica and japonica characteristics could accurately be determined via calculating the average frequency of indica- or japonica-specific alleles on different InDel loci across the rice genome. This method was named as the "InDel molecular index" that combines molecular and statistical methods in determining the indica and japonica characteristics of rice varieties. Compared with the traditional methods based essentially on morphology, the InDel molecular index provides a very accurate, rapid, simple, and efficient method for identifying indica and japonica rice. In addition, the InDel index can be used to determine indica or japonica characteristics of wild Oryza species, which largely extends the utility of this method. The InDel molecular index provides a new tool for the effective selection of appropriate indica or japonica rice germplasm in rice breeding. It also offers a novel model for the study of the origin, evolution, and genetic differentiation of indica and japonica rice adapted to various environmental changes.     

Salt tolerance of transgenic rice (Oryza sativa L.) withmtlD gene andgutD gene

Southern blot analysis indicated thatmtlD gene (encoding mannitol-1-phosphate dehydrogenase) andgutD gene (encoding glucitol-6-phosphate dehydrogenase) had been integrated into the rice genome mediated byAgrobacterium tumefaciens LBA4404(pBIGM). The expression of the above two genes in transgenic rice plants was demonstrated by Northern blot analysis and enzymatic activity assay. Analysis of sugar alcohol showed that transgenic rice plants could produce and accumulate mannitol and sorbitol. The salt tolerance of transgenic plants was much higher than that of their controls.     

Basta对水稻愈伤组织生长及分化的影响

通过研究除草剂 Ｂａｓｔａ对 ６个水稻品种愈伤组织的生长和分化的影响,发现 Ｂａｓｔａ对愈伤组织的生长和分化具有强烈的抑制作用;在此基础上,找到了合适的Ｂａｓｔａ筛选压,为以ｂａｒ基因作为选择标记基因的水稻遗传转化奠定了基础．     

转基因水稻与野生稻(Oryza nivara Sharma et Shastry)杂交后代种子萌发率

种子休眠性是野生植物重要的适应性状,通过种子萌发实验可以分析种子休眠性强弱.通过人工杂交获得转抗虫基因栽培稻与一年生普通野生稻三种组合的杂种,对杂种的F3代和F4代种子采用直接萌发、打破休眠后萌发、埋土15 d和30 d 4种不同处理来检测种子活力和萌发率.结果显示转基因杂种后代种子表现出较强的休眠性,转基因对种子活力和休眠性没有明显的影响,种子休眠性有随种子世代的增加而逐渐减弱的趋势,提示水稻转基因逃逸后有在野生稻群体中宿存和扩散的可能性,但这种可能性可能会随世代增加而下降.这为进一步研究水稻转基因逃逸风险提供了参考.     

茉莉酸甲酯对水稻幼苗呼吸代谢途径的影响

水稻幼苗在其生长过程中,叶片及根部的ＴＣＡ循环所占比重不断减少,而ＨＭＰ途径不断增强．０２５μｍｏｌ／Ｌ及０２５ｍｍｏｌ／Ｌ茉莉酸甲酯处理均能减少幼苗叶片及根部ＴＣＡ循环所占比重,增加ＨＭＰ途径所占比重,但对呼吸作用中的电子传递途径没有明显的影响．