發(fā)布時間：2018-03-30 10:14

  本文選題：水稻　切入點：致死白化突變　出處：《聊城大學》2017年碩士論文

【摘要】：植物白化是植物葉色突變的類型之一,主要是由于缺乏葉綠體色素所致。從植物發(fā)育的角度來看,葉綠體色素缺乏有兩個原因,一是葉綠體發(fā)育正常,葉綠體色素合成受阻;二是葉綠體發(fā)育不正常,類囊體發(fā)育不完全,細胞內雖能夠合成葉綠體色素,但合成的色素不能到達正確位置上發(fā)揮功能,隨時降解。因此,白化植物葉片的全部或局部葉綠體色素含量為零或痕量。水稻是全球主要糧食作物,其葉色突變與產量直接相關。從葉色突變性狀對個體生長發(fā)育影響角度來看,可分為致死突變、非致死突變和條件致死突變。其中致死突變是研究水稻葉綠體發(fā)育與光合作用的極好材料。水稻白化致死突變體在幼苗期依靠種子胚乳中儲存的營養(yǎng)物質維持生長,待種子內的營養(yǎng)物質耗盡,植株死亡。本研究以水稻白化致死突變體Osalb24為試驗材料,以野生型水稻為對照,觀察該突變體生長發(fā)育的外部形態(tài),在透射電子顯微鏡下觀察該突變體三葉期的葉綠體發(fā)育情況,用分光光度計測定葉綠體色素含量,通過基因的連鎖反應與圖位克隆技術對Osalb24基因進行了粗略定位。結果表明:(1)從種子萌發(fā)到三葉期早期,白化幼苗和野生型一樣,能夠正常生長。但是無論是地上部分的莖葉,還是地下部分的根系,白化突變體Osalb24都比野生型長得細弱。三葉期中后期白化幼苗逐漸停止生長,最后死亡。(2)在透射電鏡下觀察,Osalb24突變體葉片的葉綠體結構與野生型的一樣,都具有發(fā)育完全的類囊體,葉綠體發(fā)育正常。(3)Osalb24突變體葉片中葉綠素a和類胡蘿卜素的含量為痕量,幾乎測不出,葉綠素b的含量為0。(4)統(tǒng)計白化突變體的性狀分離比,發(fā)現白化與正常水稻性狀分離比值接近1:3,推測Osalb24屬于隱形基因。(5)通過基因的連鎖反應與圖位克隆技術,確定白化基因Osalb24位于水稻第6號染色體4,422,676bp至5,196,144bp之間。根據以上研究結果可以推斷,基因Osalb24位于水稻第6號染色體上,與水稻的葉綠體發(fā)育無關,但它影響葉綠體色素的合成�；騉salb24導致的白化性狀是隱性的,也就是說,該位點對應的顯性基因表達是水稻葉綠體色素合成不可或缺的。
[Abstract]:Plant albinism is one of the types of leaf color mutation, mainly due to the lack of chloroplast pigment. From the point of view of plant development, chloroplast pigment deficiency has two reasons: first, chloroplast pigment synthesis is blocked due to normal chloroplast development; Second, the chloroplast development is abnormal, thylakoid development is not complete, although the cell can synthesize chloroplast pigment, but the synthesized pigment can not reach the correct position to play a function, degradation at any time. The total or partial chloroplast pigment content of albino plant leaves is zero or trace. Rice is the main food crop in the world, and its leaf color mutation is directly related to yield. Can be divided into lethal mutations, Non-lethal mutation and conditional lethal mutation, among which lethal mutation is an excellent material for studying chloroplast development and photosynthesis in rice. Rice albino lethal mutant maintains its growth at seedling stage by nutrients stored in the seed endosperm. In this study, rice albino lethal mutant Osalb24 was used as experimental material and wild type rice as control. The chloroplast development of the mutant at trefoil stage was observed under transmission electron microscope. The content of chloroplast pigment was measured by spectrophotometer. Osalb24 gene was roughly located by gene chain reaction and map cloning. The results showed that from seed germination to early trefoil stage, albino seedlings could grow normally just like wild type. The albino mutant Osalb24 was weaker than the wild type in the root system. The albino seedlings stopped growing gradually in the middle and late stage of trefoil stage, and finally died.) the chloroplast structure of leaves of Osalb24 mutant was observed under transmission electron microscope, which was the same as that of wild type. The contents of chlorophyll a and carotenoid in leaves of the chloroplast mutant. The content of chlorophyll a and carotenoid was almost undetectable, and the content of chlorophyll b was 0.44) the segregation ratio of the albino mutant was calculated. It was found that the ratio of albinism to normal rice character segregation was close to 1: 3, which suggested that Osalb24 was an invisible gene. It was determined that the albino gene Osalb24 was located between chromosome 6 4422676bp and 5196144bp in rice. Based on the above results, it can be inferred that the gene Osalb24 is located on rice chromosome 6 and has no relation to chloroplast development in rice. But it affects the synthesis of chloroplast pigments. The albinism characters caused by gene Osalb24 are recessive, that is to say, the dominant gene expression corresponding to this locus is indispensable for chloroplast pigment synthesis in rice.
【學位授予單位】：聊城大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：S511

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1 張怡;徐克東;楊松;李豪;曹鵬;魏森;韋丹丹;李成偉;;，

本文編號：1685478