Variation of Seed Morphology in Local Rice Varieties from the Lower North of Thailand

Abstract

Local rice or rice landraces (Oryza sativa L.) contains the genetic diversity and variation of morphological characters, especially in seed morphology. The distinguish phenotypes of local rice lead to farmer’s selection. The objective of this study was evaluated diversity in seed morphology of local rice varieties from lower north of Thailand based on 10 morphological characters. The diversity of seed morphology was found in both within and between local rice varieties in lower north of Thailand. The highest of shannon diversity index values (H') was found in wetland rice (H’=1.426), following by upper rice (H’=1.016) and deep-water rice (H’=0.291), respectively. In addition, the variation of quantitative traits were different among wetland rice, upper rice and deep-water rice groups. The highest of seed length was found in wetland rice (10.39 mm.) whereas the highest of seed width (3.23 mm.), seed thickness (2.19 mm.) and 100 seeds weight (3.33 g.) were found in upper rice. The seed length-width ratio was classified into 4 groups, including; (1) Slender-extra long, (2) Slender-long, (3) Medium-extra long and (4) Medium-long. Such the results in the present study might be the consequence of the farmers’ selection and local adaptation.  Understanding the variation and diversity in seed morphology of local rice could be used as a guideline for ex situ conservation. Moreover, these genetic resources could also be utilized for the future rice breeding programs.