การตรวจสอบความแปรปรวนทางพันธุกรรมของพันธุ์ข้าวขาวดอกมะลิ 105 ด้วยเครื่องหมายโมเลกุล

Abstract

KDML 105 has a premium grade for cooking and eating quality and is the most popular cultivar among domestic consumers and overseas. Since it has been released in 1959, the breeder seeds of KDML 105 have been independently selected and maintained by several rice research centers in the northeastern region. There has been an observation that KDML 105 has physiologically changed from an original version. Consequently, there is a question whether KDML 105 has genetically modified or not. However, the agronomic characteristics of KDML 105 breeder seeds from 8 research centers were compared in the field at URRC. Thirty nine traits were identified and compared at 4 stages of growth, i.e. at maximum tillering, at 50% flowering, at 20-25 days after flowering and at maturity stage. Application of biotechnology to study genetic diversity of KDML 105 will be very useful for future plan in order to maintain the purity of KDML 105. The aim of this activity is to study genetic diversity of KDML 105 breeder seeds collected from 8 rice research centers in the northeast. Four replicated of each location were used for genotypic analysis using 140 primer combination of AFLP marker. One thousand and four hundred polymorphic bands were observed, which is about 10 bands per 1 primer combination. Results from cluster analysis using UPGMA indicated that among 4 replicated of 8 centers, breeder seeds from SRN and SKN had higher degree of genetic diversity with the coefficient of similarity of 0.18 and 0.14, respectively. When analyzing all 32 replicates from 8 centers, the breeder seeds from those centers could be classified into 9 groups at the coefficient of similarity at 0.10. For all 4 replicates from CPA, they could be classified into group 9, which was quite genetically different from the other groups with the coefficient of similarity at 0.20. Genetic diversity study of breeder seeds from 8 centers indicates that although they can not be differentiated by visible appearance, they may have some degree of genetic diversity. This finding will be useful for plant breeders and seed technologists to set up an appropriate plan to maintain the purity of KDML 105 in the future.