Evaluation of agro-morphological traits, seed characterization and genetic diversity of local rice (Oryza sativa L.) varieties of Pakistan

Abstract

Broad base genetic diversity is essential for a sustainable crop yield to provide tolerance against biotic and abiotic stresses. In Pakistan, rice is ranked second as a staple food and cultivated under different climatic zones. However, very little is known in terms of rice genetic diversity. The present research was performed to evaluate the genetic diversity among 12 local rice varieties by using 5 Simple sequence repeats (SSR) markers. Furthermore, agro-morphological parameters and seed quality of these varieties were studied. The maximum plant height (204.3 cm) and panicle length (40.1 cm) were observed for Hans-raj. The highest numbers of primary and secondary panicle branches were observed in Ratua-81 (51) and super basmati (62), respectively. Super basmati showed highest number of filled grains (264.3) and total number of grains (315) per panicle. The minimum days to maturity (140) was recorded for ratua-81 and highest 1000 grains weight (27 g) was recorded for Ksk-133. The highest concentration of elements, e.g. zinc (Zn) was observed in Ks-282 (44 µg/g), Iron (Fe) in hansraj (190.3 µg/g), manganese in bamla sufaid (111.3 µg/g), copper (Cu) in hansraj (856.3 µg/g), lead (Pb) in super basmati (3883.3 µg/g), and nickel (Ni) was found in basmati-385 (314.6 ug/g). For the genetic diversity analysis, five SSR markers were used and a total of 60 alleles were amplified with 20% polymorphism where RM28130 showed the highest Polymorphic information content (PIC) value (0.60). The maximum number of alleles (3) were produced by RM28089. Based on secondary panicle branches and total number of filled grains, Super basmati showed best panicle architecture and grain yield, which can be used in breeding program to develop high yielding aromatic rice genotypes. The highest number of filled grains and total number of grains per panicle were observed in super basmati, which indicated the potential adaptation. Basmati-2000, Hansraj, Ks-282, Super basmati and Basmati surkh-161 were found to be highly rich in micronutrients (iron, zinc, copper, lead and manganese). The maximum genetic distance was observed in basmati-2000 and basmati surkh 161 genotypes.