Phenotypic Characterization and Genetic Analysis of Rice with Pubescent Leaves and Glabrous Hulls (<i>PLgh</i>)

Abstract

ABSTRACT Pubescence (hairs or trichomes) of leaves is advantageous against biotic and abiotic stress, and that of hulls is disadvantageous as it interferes with field operations, such as harvesting and processing. Previous phenotypic and genotypic studies on rice ( Oryza sativa L.) pubescence used materials that had pubescent or glabrous leaves and hulls. From the National Small Grains Collection (NSGC), two accessions with pubescent leaves and glabrous hulls ( PLgh ) were identified. These PLgh accessions had more, longer, and softer trichomes on the leaves than traditional pubescent materials. Our objective was to study the inheritance of the PLgh trait. Crosses of PLgh plants with a genotype having glabrous leaves and hulls showed that leaf pubescence in the PLgh material was controlled by a dominant gene because no segregation for glabrous hull in F 2 generation occurred. Chi‐square values for 3:1 pubescent leaf and glabrous hull:glabrous leaf and hull F 2 ratio were 0.283 ( P = 0.626) and 0.919 ( P = 0.338) in two PLgh crosses, Wells × IARI 6184B and Wells × Padi Pohon Batu, respectively. However, in crosses of PLgh with three genotypes (You I B, Rondo, and Xieqingzao B) having pubescent leaves and hulls, an F 2 ratio of 12:3:1 pubescent leaf and hull:pubescent leaf and glabrous hull:glabrous leaf and hull was found in most cases, suggesting two genes were involved in the inheritance. Use of the PLgh germplasm (pubescent leaves) in rice breeding should be advantageous as a defense mechanism against biotic and abiotic stresses while avoiding the disadvantages of pubescent hulls in transportation and storage.