水稻粉狀質基因FLO6之遺傳分析與初定位

The Genetic Analysis and Coarse Mapping of the Rice Floury Gene, Floury Endosperm6 (FLO6)

廖英男(Ying-Nan Liao) ； 劉景平(Ching-Ping Liu) ； 林彥蓉(Yann-Rong Lin) ； 吳永培(Yong-Pei Wu)

《嘉大農林學報》 9卷2期 (2012/08) Pp. 1-19

https://doi.org/10.29891/JAFNCU.201208.0001

摘要

本研究以11個EMS誘變劑誘發之台稉8號胚乳外觀變異之突變品系為材料，先以碘液進行米粒胚乳之染色比色，結果發現隨著直鏈澱粉含量的增加，其胚乳會因碘液與澱粉結合上之差異，進而出現顏色深淺，此種差異在直鏈澱粉含量為12％時趨於飽和。將胚乳外觀突變品系與台中秈17號、IR64與台農78號栽培種雜交，以7個F2組合進行突變基因之遺傳分析，結果由其F2子代族群米粒胚乳外觀透明與不透明突變型的數量來看，有4個雜交組合分離比符合3：1單一隱性基因遺傳，命名為FLOURY ENDOSPERM6（FLO6），顯示造成CNY921403外觀不透明之基因控制應為單一隱性對偶基因flo6。以CNY921403與台中秈17號之雜交F2培育46個胚乳外觀不透明單株進行基因圖譜初定位，並以98個在CNY921403與台中秈17號兩親間具多型性之分子標幟，包括58個SSR、13個STS及27個Indel標幟，分析46個F2單株的基因型，結果發現46個單株之粉狀質（floury）特性與第四條染色體分子標幟RM3288、RM470具有緊密連鎖的現象，進一步在RM3288、RM470間設計一lndel分子標幟Rl04016，結果亦發現FLO6仍與RI04016呈現緊密連鎖，顯示FLO6應位於第四染色體上，基因位於區間的85.2-87.1 cM。未來可繼續擴大分析族群，利用圖譜定位選殖，將此一影響胚乳外觀表現之粉狀質基因找出，一方面供水稻白堊質形成之分子機制探討時利用，一方面則可以分子輔助選拔方式，應用於改良國內稻米白堊質表現。

關鍵字

水稻 ； 胚乳突變 ； 直鏈澱粉含量 ； 粉狀質 ； 基因定位

並列摘要

A total of 11 mutant lines, derived from Oryza sativa ssp. japonica cv. Taikeng 8 induced by EMS mutagen, were used in this study. First, the color darkness of amylose reacting with iodine solution was in proportion to the amylose contents which the reaction was reached to saturation till 12% of amylose content. Six mutant lines with abnormal endosperm were crossed to 0. sativa ssp. indica cv. Taichung Sen 17 (TCS 17), O. sativa ssp. indica cv. IR64, and O sativa ssp. japonica cv. Tainung 78, respectively. Seven F2 populations of above cross combinations were employed to genetic analysis. Four of them exhibited the segregation ratio of transparent and opaque endosperm of 3:1, revealing the phenotype was regulated by single gene, and the opaque endosperm of CNY921403 was resulted by the recessive allele.Forty six F2 of CNY921403×TCS 17 possessing opaque grain were subjected to coarse mapping of FLO6 with 98 polymorphic markers, including 58 SSR, 13 STS and 27 Indel markers. The floury character of the 46 F2 individuals was closely-linked with RM3288 and RM470 on chromosome 4. None floury locus was mapped in this region, we named the new locus as FLOURY ENDOSPERM6 (FLO6). The newly designed lndel marker, RI04016, was also linked with FLO6. As the result, the novel floury gene FLO6 is located in the interval of 85.2-87.1 on chromosome 4. This study paves the ways on positonal cloning of FLO6 for molecular investigation on grain chalkiness and on marker-assisted selection for improving rice grain quality with less or no chalkiness in Taiwan.

並列關鍵字

Rice ； Endosperm mutants ； Amylose content ； Floury endosperm ； Gene mapping