Variation in Grain Morphology of Upland Rice Varieties from Luang prabang Province Lao PDR

Abstract

Luang prabang province is recognized as a major area of the diversity of Oryza sativa L. in Lao PDR. Grain morphological characteristics can be used as the primary information of genetic variation among different rice varieties in the local germplasm which can be a source of value adding traits for rice breeding programs. The purpose of this study was evaluated variation in grain morphological characteristics of upland rice varieties from Luang prabang province, Lao PDR. The samples were collected from three districts, Ponxay (PX), Pak Ou (PO) and Xieng Ngeun (XNg), two villages each. Grain morphological characteristics were measured including grain size (length, width, and thickness), weight, shape, and endosperm type and pericarp color. The total of 60 samples were collected which was separated into 26, 10, and 24 samples from PX, PO, and XNg, respectively and among these samples 42 and 18 samples were glutinous and non-glutinous endosperm types, respectively. The 51 samples were found in non-pigmented, 4 in red and 5 in black pericarp colors. There was variation of grain size among 60 samples. Grain length, width and thickness were ranging from 8.61-11.63, 2.67-4.27 and 1.97-2.47 mm, respectively. Grain shape was determined by using the ratio of grain length/width and most samples (58 varieties) were distinguished as large grain type and the rest in slender type. One hundred grain weight was also varied from 2.05-4.04 g among brown rice of 60 samples. The grain weight was varied with grain length, width and thickness in multiple regression of y = 0.39 (grain length) + 0.53 (grain width) + 1.42 (grain thickness) – 5.52 at R² = 0.89 (p < 0.05). This study demonstrated the variation in grain morphological characteristics of upland rice varieties from Luang prabang province, Lao PDR. The variation of nutritional quality was subjected to evaluate in the further investigation which can be used as the basic information for the selection traits of rice varieties in the further breeding program.