การใช้เครื่องหมายโมเลกุลช่วยคัดเลือกในประชากรลูกผสมชั่วที่ ๒ ระหว่างข้าวก่า เจ้าสายพันธุ์ก้าวหน้า และข้าวพันธุ์สมัยใหม่ ปทุมธานี ๑

Abstract

Purple rice or black glutinous rice contains anthocyanin which provide antioxidant property as a unique characteristic compare to the white rice. Previously, "Kum Doi Saket" (KDK), purple glutinous rice was crossed with "Pathum Thani 1" (PTT1), a photoperiod insensitive white rice variety. The advanced purple rice line with photoperiod insensitivity (KDK-10), black pericarp and high anthocyanin were selected. However, KDK-10 had low yield and lack of aroma. This KDK-10 would be further improved for high yielding ability and aroma. In this study, KDK-10 was crossed with the modern variety (PTT1), evaluated and compared with their parents in F, hybrid and selection in F2 and F, generations. The objective of this study was to use molecular marker assisted selection in F2 generation for aroma and amylose content traits. This research was conducted at the experimental plot of Agronomy Division, Faculty of Agriculture, Chiang Mai University during August 2016 to December 2018 In the first experiment, the morphological traits of F1 hybrid were evaluated and compared with their parents, KDK-10 and PTT1. It was found that morphological traits of F1 hybrid deviated from their parents. The F, hybrid presented morphological characters similar to KDK-10, female parent or between parents. All morphological characters of the F1 hybrid shown black color except leaf, internode and pericarp color while days to flowering of F, hybrid were similar to KDK-10, female parent but longer than PTT1, male parent. The number of tiller per plant, number panicle per plant and 1,000 seed less weight were lower than parents. The grain yields per plant of the F1 hybrid were less than PTT1 parent. In the second experiment, selection of F2 generation, KDK-10 cross with PTT1 by planting 50 plants of each parent and 320 plants of F2 generation number with interval between plant at 25x25 centimeter. At tillering stage, leaf samples were collected. At least 3 seeds were randomly selected from individual plant to determine pericarp colors. There were 191 plants with black pericarp and 129 plant with white pericarp. It was found that the color traits of the pericarp were consistent with into 2 complementary gene controlling model. The seed with black pericarp were then selected using molecular marker FMbadh2-E7. There were 3 types of DNA fingerprint are including A is the genetic characteristic that similar to KDK-10 (Badh/Badh), B is the genetic characteristic that similar to PTT1 ( badh/badh) and H is the genetic characteristic from heterozygous ( Badh/badh). Selection only 24 plants with type B of DNA fingerprint. All have black pericarp, half of them had a yield equal to or greater than KDK-10 parent. It was found that 3 plants were equal to PTT1 parent and 1 plant produced yield more than their parents. The third experiment, evaluation of F, generation, KDK-10 cross with PTT1 were compared with their parents. It was found that 17 plants showed segregation similar to KDK-10, 28 plants were similar to PTT1. The F, generation showed segregation within family 66 plants and found that a family with all of 5 plants shown black pericarp 5 families. There were 18 families produced both black and white pericarp. For aromatic characteristic measured by sensory test, 10 test people were used to smell the scent at intervals of 10 seconds, divided into not fragrance level 0, medium fragrance level 1 and high fragrance level 2. there were 11 plants with fragrance of level 1 and more than level 1. When comparing average fragrant score, it was found that 25-5 and 167-2 plant had the highest average fragrance level of 1.8. For yield, 184-4 plant was the highest yield of 11.8g and 184-1 plant was the highest amylose percentage and when the yield per plant and the mean of fragrance or amylose content of Fs generation of each selected plant were used to determine correlation. There was no relationship between yield with 2 characteristics. However, they were competent to select the plant with high yield, fragrance of more than level 1 and amylose at the level of 10-19 percent with 2 plants. The hybrids which were selected from this study will be use as genetic materials for the development of new rice variety with photoperiod insensitivity, high yield and aroma in the future