Sex ratio and genetic diversity in the dioecious Pistacia atlantica (Anacardiaceae)

Abstract

The levels of genetic variation in dioecious plant species have been reported to differ between male and female populations. This has been attributed to different factors including distribution patterns of individuals, sex ratio and also stochastic events. We measured the levels of genetic diversity in male and female populations of dioecious Pistacia atlantica (pistachio, Anacardiaceae) separately for each region and genders in two eco-geographically different regions over 350 km apart and of different population sizes in East Azerbaijan, Iran by randomly sampling 15 individuals of male and female from each of the regions using randomly amplified polymorphic DNAs. The percentage of polymorphic RAPD bands in the male populations of dioecious Pistacia atlantica was significantly higher (88.9%) than that of female populations (80.8%), and similarly, male populations had greater genetic diversity (0.387, Shannon; 0.252, Nei's) compared to female populations (0.381, Shannon; 0.249, Nei's). Genetic variation in larger population (Arasbaran) of P. atlantica (0.387, Nei's) was greater than that of the smaller (Jazire) population (0.312), indicating the impact of population size on genetic variation. Partitioning the total genetic variation using an analysis of molecular variance indicated that 77% of total genetic diversity was allocated within populations while 23% of this variation was dedicated among populations.

Genetic diversity analysis among male and female Jojoba genotypes employing gene targeted molecular markers, start codon targeted (SCoT) polymorphism and CAAT box-derived polymorphism (CBDP) markers

“…Comparison of the genetic polymorphism between male genotype population and female genotype population by SCoT and CBDP markers revealed that the male genotype populations in both cases yielded higher polymorphism and PIC, MI, Rp values than the female populations. This is in agreement with the reports on Pistacia atlantica ( Nosrati et al, 2012 ) and S. chinensis ( Sharma et al, 2009 ). Nosrati et al (2012) concluded from their study that higher levels of genetic variation in male populations resulted due to the higher number of male plants and even distribution of males than females.…”

“…This is in agreement with the reports on Pistacia atlantica ( Nosrati et al, 2012 ) and S. chinensis ( Sharma et al, 2009 ). Nosrati et al (2012) concluded from their study that higher levels of genetic variation in male populations resulted due to the higher number of male plants and even distribution of males than females. Similar interpretation could be drawn for Jojoba because of its male biased population (5:1; male:female ratio) in nature.…”

“…The dendrograms were mainly clustered into two major groups, one representing all the female genotypes and another showing all the male genotypes, indicating an apparent gender-based distinction among the Jojoba genotypes. Similar clustering of the males and females separately in a dendrogram had also been reported earlier in dioecious taxa such as Actinidia deliciosa ( Shirkot et al, 2002 ); Piper betle ( Verma et al, 2004 ), S. chinensis ( Sharma et al, 2009 ), Pandanus tectorius ( Panda et al, 2010 ) and P. atlantica ( Nosrati et al, 2012 ). Based on the aforesaid findings, it is concluded that Jojoba genotypes collected from AJORP are genetically diverse and the breeders can choose the most diverse parents for breeding programs and for its germplasm collection and management.…”

Homogenous genetic structure in populations of <i>Taxus baccata</i> with varied proportions of male and female individuals

“…Their analysis revealed minimal significant differences in the values of the tested parameters (H e , H o , A/L), which they suggested to be due to the different number of male and female individuals in the populations and the influence of genetic drift on allele frequencies in the populations. Additionally, Nosrati et al (2012) measured levels of genetic diversity for male and female individuals of the dioecious atlantic pistachio (Pistacia atlantica Defs.) using RAPD markers.…”

Effects of Landscape Fragmentation on Genetic Diversity of Male-Biased Dioecious Plant Pistacia chinensis Bunge Populations

“…Many studies have shown that landscape fragmentation may lead to a biased sex ratio in dioecious plant populations [10,11]. Biased sex ratios may further influence the genetic diversity, but the consequences may be different for different species [12][13][14]. Vandepitte et al [15] observed that genotypic diversity decreased with more male-biased sex ratios in the dioecious forest perennial Mercurialis perennis L. Hilfiker et al [12] studied the small populations experiencing genetic drift and revealed an increased sex ratio bias toward females in the dioecious conifer Taxus baccata L. Thus, dioecious plants may differ greatly in their responses to landscape fragmentation.…”