Genetic relationship among Labisia pumila (Myrsinaceae) species based on ISSR-PCR.

The genus Labisia (Myrsinaceae) is a popular medicinal plant in Malaysia. We examined the genetic relationship among three varieties of L. pumila var. pumila, L. pumila var. alata, L. pumila var. lanceolata and Labisia paucifolia using an ISSR assay. Fifty-eight primers were tested, among which 18 gave reliable polymorphic banding patterns; these yielded 264 polymorphic markers. A similarity matrix was used to construct a dendrogram, and a principal component plot was developed to examine genetic relationships among varieties. Jaccard's similarity coefficient among species ranged from 0.09 to 0.14. At a similarity of 0.117%, species were divided into two main clusters. The mean value of the observed number of alleles, the effective number of alleles, mean Nei's gene diversity, and Shannon's information index were 1.98, 1.64, 0.38, and 0.57, respectively.

Bulked segregant analysis for relative water content to detect quantitative trait loci in wheat under drought stress.

This study was carried out to evaluate the genetic effect of quantitative trait loci (QTLs) conferring drought tolerance in wheat. A population of 120 F(2) individuals from the cross between the drought-tolerant S-78-11 and drought-sensitive Tajan cultivars were analyzed for their segregation under drought stress conditions. The relative water content under drought stress conditions exhibited continuous variation, indicating the minor gene effects on the trait. Single-marker analysis (SMA) was carried out to detect the main QTL association with drought tolerance. The SMA results revealed that the simple sequence repeat markers GWM182 and GWM292 on chromosome 5D and GWM410 on chromosome 5A exhibited significant association with drought tolerance, accounting for 30, 22, and 21% of the total variation, respectively. The 3 genetic loci, especially GWM182, can be used in marker-assisted selection methods in drought tolerance breeding in wheat.