Evaluation of Progeny Populations Between Purple Rice with High Grain Phenol cv. Saeng 5 and Modern Variety cv. Pathum Thani 1

Abstract

Khao Saeng 5 (KS5) is a “Khao Kam” with purple kernel and contained high phenol content in rice grain. It is traditional improved variety by pure line selection method from purple rice landraces in the highlands of northern Thailand. Phenolic compounds are considered as essential substances found in purple rice with antioxidant properties help to reduce the risk of various major chronic diseases. However, KS5 is a landrace rice variety with lower yielding than the modern varieties. Therefore, to improve KS5 with higher yields, the hybridization was conducted between KS5 and the modern white rice variety Pathum Thani 1. This study aimed to evaluate the agronomical characteristics of first- and second-generation hybrids and select plants with high phenol content from the second - generation population. The results showed that almost agronomical characteristics of F1 plants grown in wet season 2017 was ranged between KS5 and PTT1, excepted plant height had exceeded their parents, while the percent of filled grain was lower than their parents. In dry season 2018, the 129 F2 plants with purple pericarp were selected from 280 F2 plants. Almost all the selected purple pericarp F2 plants had the range of almost agronomical characters wider than their parents, except the percentage of filled grain was lower than female parent KS5. Grain yield was varied between 6.2 - 56.5 g / plant and skewed to KS5. Phenol content showed a continuous distribution ranging from 28 to 272 mg gallic acid equivalent/100 g. There was no relationship between grain yield and phenol content. The eight F2 plants with the highest grain phenol ranging from 199.7 - 272.3 mg gallic acid equivalent / 100 g and grain yield ranging from 7.6 - 34.2 g / plant were selected. These F2 plant could be used as the genetic sources for subsequence selection to improve high grain quality purple rice.