诱发温度敏感型水稻叶色突变体的研究

在用６０Ｃｏγ射线辐照诱发的温敏核不育水稻叶色突变体中，发现有４个突变体的叶色表达与温度有关。突变体Ｗ４、Ｗ１１在高温（３０～３５℃）叶片呈白色，在低温下（２０～２５℃）表现为黄色或浅黄色。３５℃时叶绿素（ａ＋ｂ）含量分别为０．０２１９和０．０５３６ｍｇ／ｇ鲜重，而在２５℃时分别上升到０．２４１０和０．３４３１ｍｇ／ｇ鲜重，增长幅度达１０倍左右。相反，突变体Ｗ１７和Ｗ２５在低温下表现为白色，高温下转为浅绿色。在２５℃时叶绿素含量分别只有０．０８１３和０．０１７２ｍｇ／ｇ鲜重，在３５℃时分别上升到１．０５７０和１．１３６７ｍｇ／ｇ鲜重，增长幅度高达９０倍以上。在此温度范围内，对照２１７７Ｓ的叶绿素含量在同一数量级内变化。在生长过程中，上述突变体的叶片均可转换成黄绿色或绿色，并开花结实。在２５℃下生长到３．５叶期时，Ｗ４和Ｗ１１的叶绿素含量已接近２１７７Ｓ的水平，分别达到对照的８８．６％和８１．１％。但Ｗ２５在２０℃及以下温度生长时，叶片始终呈白色，不发生转换，从而表现出条件致死的特性。

Temperature-sensitive leaf color mutation in rice (Oryza sative L.)

Studies were undertaken on the leaf color appearance of 4 cholrophyll-deficient mutation lines both in field and in phytotron.The mutation lines W4,W11,W17,and W25,which were induced by 60℃ Co gamma rays,showed white or yellow at seedling stage ,and could be distinguished from their parental TGMS line 2177s and any other rice materials.The results showed that temperature could heavliy influence the expression of leaf color in the mutation lines .It was white at 30～35℃,yellow or yellowish at 20～25 ℃ for the lines of W4 and W11,and white at 20～25℃ and greenish at 30～35℃ for the lines of W17 and W25,.The parent 2177s showed normal green and had the chlorophyll content betweeen 2.018 and 2.118(mg/g.f.w.) Except the W11 which showed yellow or light green all its life,all the mutation lines could convert to normal green after the forth leaf extension.W25 maintained white when grown at the temperature bellow 20℃,which indicated it was a condition lethal mutant.