杂交水稻抽穗期遗传研究——Ⅳ.光周期敏感性的遗传

在福州(26.05°N)自然条件下,用3个不感光的不育系:V_(20)A,宁A和珍鼎28A;3个基本不感光的恢复系:5460,IR_(30)和明恢63分别与两个感光的恢复系:印尼矮禾和红田谷杂交,共配制13个组合,调查其抽穗期表现,结果表明:13个组合中,除2个组合F_1表现为感光性不完全显性,F_2呈1:2:1分离外,其余组合均表现为感光对不感光或基本不感光显性,F_2分离为3感光:1不感光或基本不感光。表现为1对主效感光基因的差异。     

水稻抽穗期基因研究进展

抽穗期是水稻品种的重要农艺性状之一,它对于水稻适应不同的栽培地区和耕作季节是至关重要的。近年来,在水稻抽穗期基因的发掘、定位、克隆及作用机制等方面,特别是QTL研究方面取得较大进展。在此,回顾了水稻抽穗期基因/QTL的定位和克隆,阐述QTL的互作及与主基因的等位性关系,并通过和拟南芥模式植物的对比进一步阐述了水稻开花的分子机制,为研究禾本科植物的抽穗期基因提供了有意义的启示。旨在为中国水稻抽穗期基因遗传以及在育种上的应用提供理论依据。     

水稻开花时间决定的光周期途径分子调控机制研究进展

植物的开花受到光、温、营养条件等环境因素和自身发育进程的影响。光作为一个最重要的环境因素,不仅能为植物提供能量,还对成花决定起着重要作用。综述了水稻光周期开花调控途径的最新研究进展,以期为水稻开花的研究提供参考。     

水稻抽穗期的遗传学研究

该文阐述了水稻抽穗期的遗传研究进展。水稻抽穗期的多样性是由于感光性与基本营养生长特性的多样组合形成的 ,其复杂的遗传表现是由多个感光基因及其修饰基因、基本营养生长性基因及其修饰基因综合作用的结果 ,并概述了水稻抽穗期基因的定位及QTL定位的现状 ,讨论了水稻抽穗期遗传研究中存在的问题及未来研究的方向。     

不同群体水稻抽穗期主要株型指标的研究

以汕优63和武运粳8号为材料,测定了抽穗期的若干株型因子,并对不同群体的株型因子进行了比较。结果表明,高产群体的茎蘖发展合理,成穗率高,株高较矮,上部叶片的叶角小,叶片趋向挺直,叶片的相对高度较高,叶面积适中,叶片的叶绿素含量高。     

水稻品种南京11抽穗期的基因型分析

 用抽穗期感光基因型已知的秋光（e1e1　e2e2　e3e3　Se1eSe1e）、越光（E1E1　E2E2　e3e3　Se1eSe1e）、日本晴（E1E1　e2e2　e3e3　Se1Se1）和日光（E1E1　E2E2　e3e3　Se1Se1）作鉴别品种,分析了中籼水稻品种南京11的抽穗期基因型。结果表明,南京11的抽穗期感光基因型为 E1E1e2e2E3E3Se1Se1,同时还存在1对隐性感光抑制基因i-Sel;进一步利用QTL近等基因系NIL（Hdi）和NIL（Hd4）进行的试验也验证了南京11存在2个显性的主效感光基因E1和Se1。     

寒地水稻抽穗期的灰色关联分析

对寒地水稻抽穗期的灰色关联分析表明 ,对寒地水稻抽穗期影响较大的因素依次是移栽后第 2周积温、秧苗期积温、移栽时秧龄和移栽期等 ,而移栽后第 7周积温、主茎叶片数、播种期和移栽后第 1周积温等对抽穗期的影响较小。     

不同水稻品种抽穗期对高温的响应及避热的调控措施

采用盆栽试验研究不同水稻品种(系)在抽穗期对高温的响应,用盆栽和大田种植2种方式研究不同播期处理对水稻的抽穗期避热调控效果,在南京和如皋两地试验田研究不同的增施穗肥处理对水稻抽穗期的影响。结果表明:①在抽穗期高温处理试验中,16个参试水稻品种(系)中有2个品种(系)(Z2001和86优8)表现为耐高温,2个品种(农垦57和武香粳14号)表现为中耐,其余12个品种属高温敏感型;②不同播期处理对水稻抽穗期的调控效果明显,综合历年气象资料,在长江流域水稻生产中,为避免抽穗期高温危害,适播期宜安排在5月20日之后;③通过增加穗肥来延迟水稻抽穗时间的效果甚微。     

杂交水稻不育系博A的抽穗期基因型分析

本研究以抽穗期主基因近等基因系EG0~EG7(检测E位点),ER~LR(检测Se-1位点),T65,T65m,T65Eb,T65Ebm为测验系,在江西南昌(28°68′N)自然长日照(14~16 h/d)和人工遮光短日照诱导(10 h/d)处理条件下,对保持系博B,以及“TLs×博B”F1、F2代的抽穗期进行了调查。对影响博B抽穗期的基因分析结果表明,博B在E1、E3位点分别带有隐性非感光早熟基因e1和显性感光迟熟基因E3,在Se-1位点带有显性感光基因Se-1n,在Ef-1位点带有隐性迟熟基因ef-1。由此推断博A的抽穗期基因型为e1e1E3E3Se-1nSe-1nef-1ef-1。博A带有隐性非感光早熟基因e1,显性感光迟熟基因E3,在性状上表现为早熟;带有显性感光基因Se-1n,隐性迟熟基因ef-1,可保证其具有一定长度的基本营养生长期;但与带感光等位基因E1的恢复系配组,其F1将表现为迟熟。以不同光照条件下“TLs×博B“F2植株抽穗期分布频次和平均抽穗期的差异,对影响抽穗的基因效应进行了估计分析,对以博A为不育系配置的杂交水稻组合的广适性遗传基础也进行了讨论。     

蔗糖对灌浆期水稻籽粒中蔗糖合酶活性的影响

蔗糖合酶是一种参与植物体内蔗糖代谢的重要酶。实验采用了离体穗培养技术研究蔗糖对蔗糖合酶活性的调节作用。结果表明,蔗糖处理显著提高了水稻籽粒中蔗糖合酶活性,而且蔗糖合酶活性随着蔗糖浓度增加而增加。当用同浓度渗透调节剂甘露醇、山梨醇和氯化钾,及其它单糖如葡萄糖、果糖,以及两者混合物等代替蔗糖处理,都不能产生与蔗糖相同的效应。说明蔗糖对蔗糖合酶活性的影响并不是渗透胁迫引起的。     

QTL Detection and Epistasis Analysis for Heading Date Using Single Segment Substitution Lines in Rice （Oryza sativa L.）

Heading date of rice is a key agronomic trait determining cultivated areas and seasons and affecting yield. In the present study, ifve primary single segment substitution lines with the same genetic background were used to detect quantitative trait loci （QTLs） for heading date in rice. Two QTLs, qHD3 and qHD6 on the short arm of chromosome 3 and the short arm of chromosome 6, respectively, were identiifed under natural long-day （NLD）. Nineteen secondary single segment substitution lines （SSSLs） and seven double segments pyramiding lines were designed to map the two QTLs and to evaluate their epistatic interaction between them. By overlapping mapping, qHD3 was mapped in a 791-kb interval between SSR markers RM3894 and RM569 and qHD6 in a 1 125-kb interval between RM587 and RM225. Results revealed the existence of epistatic interaction between qHD3 and qHD6 under natural long-day （NLD）. It was also found that qHD3 and qHD6 had signiifcant effects on plant height and yield traits, indicating that both of the QTLs have pleiotropic effects.     

MATE转运蛋白在水稻抗逆作用中的研究进展

水稻 Oryzasativa在生长发育过程中需要面对自然环境中多重不利因素的影响,包括非生物胁迫和生物胁迫。为了抵御这些不利因子,水稻在自然选择过程中形成了多种机制以保护植株的健康生长。多药物有毒化合物排出家族转运蛋白（Multidrug and toxic compound extrusion family ,MATE family）是植物体中一类新型大家族蛋白,它们在细胞的解毒机制中起重要作用。本文介绍了MATE蛋白的基本特征、分子机制和生物学功能以及目前在水稻抗逆作用中的研究概况,以期为水稻抗胁迫研究提供新的思路和理论参考。     

开花期高温胁迫对不同水稻品种花粉萌发和结实的影响

以5个籼稻品种为材料,通过抽穗期高温处理和离体花粉萌发等试验,研究了开花期高温对水稻花粉萌发和结实的影响.结果表明,不同品种水稻对高温处理的敏感度明显不同,其中品种黄华占在高温处理4 d后的花粉萌发率达到70%以上,在高温处理7 d后小穗结实率仍保持50%左右,其他4个品种的花粉萌发率和小穗结实率都明显低于黄华占,由此认为,黄华占是一个耐热性较强的品种.     

寒地水稻种质资源稻瘟病抗性研究

为了筛选出优异的水稻稻瘟病抗性材料,收集并整理我国黑龙江省、吉林省、辽宁省以及日本、韩国共203份水稻种质资源,按照不同的育成时期、来源进行分类,利用2a的抗病鉴定结果进行资源评价。结果表明:旱育稀植时期育成的品种稻瘟病抗性有很大的提高,韩国的水稻资源有更好的稻瘟病抗性。资源的年际间抗性有差异,应对材料进行多年、多点的鉴定。因此,在利用自然条件对育种材料抗稻瘟病筛选后,用接菌的方式对自然感病筛选出的未发病材料进行接菌鉴定能提高抗病鉴定的准确性。     

QTL Detection and Epistasis Analysis for Heading Date Using Single Segment Substitution Lines in Rice(Oryza sativa L.)

Heading date of rice is a key agronomic trait determining cultivated areas and seasons and affecting yield. In the present study, five primary single segment substitution lines with the same genetic background were used to detect quantitative trait loci(QTLs) for heading date in rice. Two QTLs, q HD3 and q HD6 on the short arm of chromosome 3 and the short arm of chromosome 6, respectively, were identified under natural long-day(NLD). Nineteen secondary single segment substitution lines(SSSLs) and seven double segments pyramiding lines were designed to map the two QTLs and to evaluate their epistatic interaction between them. By overlapping mapping, q HD3 was mapped in a 791-kb interval between SSR markers RM3894 and RM569 and q HD6 in a 1 125-kb interval between RM587 and RM225. Results revealed the existence of epistatic interaction between q HD3 and q HD6 under natural long-day(NLD). It was also found that q HD3 and q HD6 had significant effects on plant height and yield traits, indicating that both of the QTLs have pleiotropic effects.     

Overexpression of a Cytosolic Ascorbate Peroxidase Gene,OsAPX2, Increases Salt Tolerance in Transgenic Alfalfa

Alfalfa （Medicago sativa L.） is an important forage crop in the world and it is of great signiifcance for the improvement of its salt tolerance. To improve salt tolerance in alfalfa, a rice ascorbate peroxidase gene （OsAPX2） was introduced into alfalfa using Agrobacterium tumefaciens-mediated transformation with marker gene bar. The different T-DNA insertions in T1 transgenic alfalfa were identiifed by Southern hybridization. Three independent T2 transgenic lines were selected for stress analysis and the results showed that all of them were salt tolerant compared with wild-type plants. The transgenic plants had low levels of H2O2, malondialdehyde and relative electrical conductivity under salt and drought stresses. Moreover, the contents of chlorophyll and proline, and APX activity were high in transgenic plants under salt and drought stresses. Taken together, the overexpression of OsAPX2 enhances salt tolerance in alfalfa through scavenging reactive oxygen species.     

Effects of Farm Yard Manure and Lime on Cadmium Uptake by Rice Grown in Two Contaminated Soils of Chittagong

A pot experiment was conducted to evaluate the efficiency of farm yard manure （FYM） and lime （calcium carbonate） on reducing the uptake of Cd by rice in two Cd contaminated soils of Chittagong. The effects of farm yard manure, lime and farm yard manure mixed with lime （FYM ＋ Lime） on rice （Oryza sativa L.） growth, Cd uptake by rice and 0.1 N HC1 extractable Cd in soil were investigated. Results showed that addition of lime and farm yard manure mixed with lime significantly decreased 0.1 N HCl extractable Cd in the city sewage soil. Application of farm yard manure significantly decreased Cd concentration in rice in the city sewage soil. Lime and farm yard manure mixed with lime significantly reduced Cd concentration in rice m both the contaminated soils. Lime was more efficient than farm yard manure in reducing the uptake of Cd by rice.     

水稻基因组序列研究进展

水稻是世界上最重要的粮食作物之一,是禾本科植物的模式植物。综述了基于图位克隆的水稻基因组序列,基因组大小为389 Mb,包括37 544个非转座因子相关蛋白的基因。95%的基因组序列被精确测定,包括全部的常染色质、2个完整的着丝点及6条完整的染色体。基因组中串联重复序列占14%,平均每Mb为51个SSR。SwaI光学限制性(酶切)图谱的构建使图距缩短了11%,使基因组大小变为382.17 Mb。