Comparison of tests for the analysis of vigor and viability in paddy germplasm and their relationship to field emergence

Abstract

We assessed the vigour and viability in selected land races grown in foot hills of Himalayan region (31.1048 °N; 77.1734 °E) mainly Himachal Pradesh. The objective of this study was to compare tests used to identify vigor in paddy seeds and to establish a model that relates the seeds’ vigor, as determined in the laboratory, with field emergence. It was observed that all the genotypes were significantly different for all the tests and exhibited dormancy, as the germination percentage (%) in fresh seeds was very less but after 6 months storage and accelerated aging, it was above than minimum seed certification standards. Likewise, first count of seed germination test of rice could not prove to be good indicator of germination; however, such observation should only be recorded at final count stage. These results were confirmed by accelerated aging test, where fresh seeds were exposed to accelerated aging and their germination percentage was enhanced, which implies that during storage, the dormancy of rice seeds break down. The result on vigour index-I and vigour index-II also indicated less vigour in freshly harvested seeds. It was evident that with the increase in germination through various tests, the vigour index also increased proportionately. But all the germplasm was significantly differ from each other in respect to all the observed parameters. Assays for accelerated aging, controlled deterioration and tetrazolium showed the closest correlation to field emergence.