Relationship between leaf photosynthetic function at grain filling stage and yield in super high-yielding hybrid rice (Oryza sativa. L)

The characteristics of dry matter production before and after heading and the relationships between photosynthesis of flag leaves and dry matter accumulation in panicles were investigated on super high-yielding rice cv. Xieyou 9308 (the yield of up to 12 t/ha) with rice cv. Xieyou 63 as a control. The results showed that (i) the capacity of dry matter production before and after heading in Xieyou 9308, i.e. biomass and daily dry matter production, was remarkably higher than that in Xieyou 63, especially after heading; (ii) CO2 assimilation capacity in flag leaves in Xieyou 9308, namely Leaf Source Capacity (LSC), was also significantly higher than that in Xieyou 63, and the supply of photosynthate in leaves and the demand of grain filling were completely synchronous in Xieyou 9308, but photosynthetic function in flag leaves in Xieyou 63 declined sharply 20 days after heading and it was not enough to meet the demand of grain filling. These results confirmed that high efficient photosynthetic function in     

水稻品种对白背飞虱的抗源筛选及其抗性遗传分析

通过抗性鉴定,筛选出6个抗白背飞虱的国内品种:鬼衣谷、大花谷、大齐谷、便谷、滇瑞336.3和HA 79317-7(前4个品种均系云南地方品种)。遗传分析证明,这6个品种对白背飞虱的抗性均受单显性基因控制。HA 79317-7的抗性基因与Wbph1等位,滇瑞336-3的抗性基因与Wbph2等位。鬼衣谷、大齐谷、大花谷和便谷的抗性基因均与Wbph1、Wbph2非等位。它们与Wbph3、Wbph5的等位关系还有待进一步研究。     

水稻顶节间长度控制基因(EUI)的精细定位

通过对一水稻顶节间特异伸长突变体Mh-1进行经典遗传学和基因定位分析,认为该表型是一个核基因隐性突变所致。利用Mh-1与正常的T65-sd1杂交的F2群体对该位点定位研究分析,发现其与水稻第5条染色体长臂STS标记E30531和CAPS标记C903连锁,遗传距离分别为6．7cM和2．8cM。经进一步发展新的分子标记,将该基因精确定位在0．3cM的区域,为进一步克隆和研究该基因的分子机制奠定基础。     

水稻不同品种的穗发芽及其对外源激素的反应

选择8份早籼稻品种在开花后不同天数取穗子进行保湿培养,观察其抗穗发芽能力的差异。结果显示不同品种之间的抗穗发芽能力存在较大差异;处理以开花后22d左右的穗子保湿培养6d考查穗发芽,就能较好地比较出品种之间的差异。以3种不同浓度的赤霉素(GA3)和脱落酸(ABA)进行溶液培养,30mg／kg的赤霉素有明显促进穗发芽的效果,脱落酸抑制穗发芽的效果在不同品种之间表现出比较大的差异。     

高秆突变体Mh-11的株高遗传研究

Mh-11是从矮秆品种桂朝2号辐射诱变后代中产生的高秆突变体.用Mh-11与sd-11矮秆、非sd-11矮秆和普通高秆材料杂交,通过对F1、F2、F3 等世代以及测交后代的株高进行遗传分析,结果表明Mh-11的高秆特性是由1对隐性抑制基因控制的.该抑制基因能调节sd-11基因的表达,而对由非sd-11基因控制的矮秆没有抑制作用,这一隐性抑制基因暂时被定名为i-sd-11(t).还讨论了该基因的遗传学意义和可能的育种利用价值.     

Relationship between leaf photosynthetic function at grain filling stage and yield in super high-yielding hybrid rice (<Emphasis Type="Italic">Oryza sativa</Emphasis>. L)

The characteristics of dry matter production before and after heading and the relationships between photosynthesis of flag leaves and dry matter accumulation in panicles were investigated on super high-yielding rice cv. Xieyou 9308 (the yield of up to 12 t/ha) with rice cv. Xieyou 63 as a control. The results showed that (i) the capacity of dry matter production before and after heading in Xieyou 9308, i.e. biomass and daily dry matter production, was remarkably higher than that in Xieyou 63, especially after heading; (ii) CO₂ assimilation capacity in flag leaves in Xieyou 9308, namely Leaf Source Capacity (LSC), was also significantly higher than that in Xieyou 63, and the supply of photosynthate in leaves and the demand of grain filling were completely synchronous in Xieyou 9308, but photosynthetic function in flag leaves in Xieyou 63 declined sharply 20 days after heading and it was not enough to meet the demand of grain filling. These results confirmed that high efficient photosynthetic function in leaves after heading and its complete synchronization with grain filling are the key approaches to super high yield of rice.     

栽培稻—药用野生稻杂种F1及回交后代的基因组原位杂交鉴定

以ｄｉｇｏｘｉｇｅｎｉｎ标记的药用野生稻总ＤＮＡ作探针,未标记的栽培稻总ＤＮＡ封阻,地栽培稻－药用野姓稻Ｆ１及回交皇代材料根尖体细胞染色体制片进行基因组原位杂交,鉴定出３个双单体异源附加系和４个单体异附加系。当标记探针用ａｎｔｉ－ｃｄｉｇｏｘｉｇｅｎｉｎ－ＰＯＤ和ＤＡＢ检测时,药用生稻染色体显棕色,栽培稻染色体则因Ｇｉｅｍｓａ.地染而显浅蓝色;标记探针用ａｎｔｉ－ｄｉｇｏｘｉｇｅｎｉｎ－ＦＩＴＣ检     

超高产杂交稻灌浆期光合功能与产量的关系

以杂交水稻协优63为对照, 对亩产800 kg以上的超高产杂交水稻组合协优9308抽穗前、后的物质生产特性及剑叶光合作用与穗部物质积累的关系进行研究. 结果表明: (ⅰ) 与协优63相比, 协优9308抽穗前、后的物质生产能力无论生物量还是日干物质生产量, 均极显著高于协优63, 尤以抽穗后更为明显. (ⅱ) 协优9308剑叶的光合碳同化能力(叶源量)极显著高于协优63, 且能够切合籽粒灌浆需求, 在单株水平上其净同化产物基本满足籽粒灌浆的需求, 而协优63抽穗后20 d左右剑叶光合功能快速衰退, 单株净同化产物不能满足籽粒灌浆的需求. 结果证明, 灌浆后期仍能保持高效光合功能、并且能够切合籽粒灌浆需求是实现水稻超高产的关键环节.     

杂交水稻汕优63杂种纯度的RAPD鉴定

使用纯度低或真实性差的杂交种子会给农业生产造成极大损失。然而杂交种子的纯度无法单纯从种子形态上鉴别．本文首次采用ＲＡＰＤ特异扩增谱带做为分子标记对水稻杂交种纯度进行了鉴定。汕优６３杂交水稻种子由中国水稻研究所从某制种单位随机取样获得。珍汕９７Ａ不育系和明恢６３恢复系等品种由中国水稻研究所提供。在做形态观察的同时,分别取上述三种材料叶片制备ＤＮＡ作为初始模板ＤＮＡ。对３００个ＲＡＰＤ随机引物,经过三次多态性初筛复筛,发现随机引物Ｐ１８可以稳定地扩增出一条来源于父本明恢６３的０．８ｋｂ的特异条带。用Ｐ１８引物对１００株汕优６３杂交单株进行ＲＡＰＤ扩增,其中８３个获得了０．８ｋｂ特异条带（Ｆｉｇ．１ｕｐｐｅｒ）。分子杂交证明其结果是可靠的（Ｆｉｇ．１Ｌｏｗｅｒ）。以ＲＡＰＤ扩增结果为依据,对这１００株材料进行植株形态比较,发现那１７个不能扩增出特异条带的单株均为假杂种。说明该制种单位汕优６３的假种率为１７％。大大超过农业部的有关规定。应对其原因和后果进行追究。用Ｐ１８引物对１８种分别为籼粳及其中间型的常用稻种进行ＲＡＰＤ扩增鉴定,除明恢６３的亲本──圭６３０和中间型Ｐｃｃｏｓ,Ａｕｓ３７３具有０．８ｋｂ的特异条带