Czech Journal of Genetics and Plant Breeding - In Press
The synergistic interaction of low concentrations of IAA and GA promotes the separation of the dehiscence zone within the pod ventral suture in vegetable soybeansOriginal Paper
Bingjie Tu, Changkai Liu, Qiuying Zhang, Xiaobing Liu, Nan Xu
Pod dehiscence, also known as pod shattering, refers to the process by which fully mature pods open and release their seeds upon reaching physiological maturity. The premature release of seeds from mature pods of vegetable soybean (Glycine max L.) is a significant factor contributing to yield loss in seed production. The dehiscence process occurs specifically within the dehiscence zone. To better understand the physiological mechanisms underlying dehiscence zone degradation of pod shattering in vegetable soybean dehiscence zone, we conducted a comparative analysis of pectinase, polygalacturonase (PG), cellulase Indole-3-acetic acid (IAA), Gibberellin (GA) Abscisic acid (ABA) and Zeatin (ZA) in pod ventral suture by comparing with indehiscent grain soybeans. The pod ventral suture of dehiscence vegetable soybeans exhibits significantly higher activities of pectinase, polygalacturonase, and cellulase, while displaying lower contents of indole-3-acetic acid (IAA) and gibberellin (GA). Lower concentrations of IAA and GA in the dehiscence zone enhance cellulase, pectinase, and polygalacturonase activities, accelerating cell wall dissolution, increasing cell lignification, and thereby promoting pod dehiscence.
Genetic diversity of selected Malaysian rice accessions using microsatellite markersOriginal Paper
Shahril Ab Razak, Alny Marlynni Abd Majid, Rahiniza Kamaruzaman, Norliza Abu Bakar, Rabiatul Adawiah Zainal Abidin, Yun Shin Sew, Norfarhan Mohd Assaad, Mohd Ikmal Asmuni, Noraziyah Abd Aziz Shamsudin
Genetic diversity of plant genetic resources provides the starting point for plant breeders to develop high-yielding rice varieties tolerance to biotic and abiotic stresses. Given the abundance of genetic resources available, an effective approach to characterize the materials is desired. In this study, we characterized 182 Malaysian rice accessions, which were selected based on maturity periods, using microsatellite markers. The analysis of 182 selected rice accessions using 20 polymorphic SSR markers revealed the presence of 183 alleles which ranged from two (RM507) to 22 (RM154), with an average of 9.15 alleles per locus. The observed and expected heterozygosity ranged from 0.000 to 0.506 and 0.319 to 0.864, respectively. The polymorphic information content value (PIC) values ranged from 0.2744 (RM495) to 0.8475 (RM154), with an average of 0.6216 per locus. The UPGMA dendrogram analysis showed the presence of two major groups: Group I and Group II. Generally, the varieties were grouped based on their adaptive ecosystem groups, with most lowland varieties including lowland breeding lines (92.4%) being grouped in Group I while most of the upland rice varieties (86.7%) were grouped in Group II. Additionally, the dendrogram analysis was further supported by the STRUCTURE analysis, which yielded K = 2 as the optimal number of clusters, suggesting that the studied accessions were structured into two major genetic groups. Principal coordinate analysis (PCoA) further supported this grouping pattern, with the first three axes explaining 39.63% of the total variation. Analysis of molecular variance (AMOVA) revealed that 31% of the total variation occurred among populations, 63% among individuals, and 6% within individuals. This study also showed the possibility of duplication occurrence in the tested accessions. The analysis has provided insights for future breeding programmes towards the development of high-yielding rice varieties with diverse genetic bases and to support conservation management programmes.