Evidence For Seed Vigor Associated With Fatty Acids And Its Composition In Rice

Although fatty acids (FAs) adversely influence seed vigor in general, knowledge is limited about effects of FAs and its composition on seed vigor of rice (Oryza sativa L.). In this study, seed vigor parameters, FA, and its composition contents of different rice varieties were measured to determine their intrinsic relationships. There were significant differences in germination potential (GP), germination rate (GR), field emergence rate (FER), and FA and its composition contents among different varieties in 2014 and 2015. Additionally, the results of correlation analysis in both years showed that FA content was significantly negatively associated with GP (r = -.66* and r = -.69*, respectively), GR (r = -.72* and r = -.87*, respectively), and FER (r = -.51* and r = -.51*, respectively). Interestingly, the contents of palmitate acid (C16:0), linoleic acid (C18:2), and linolenic acid (C18:3) in both years were significantly negatively related to seed vigor (r = -.43* to -.77*). Moreover, the results of principal component analysis showed that palmitate acid (C16:0), linoleic acid (C18:2), and linolenic acid (C18:3) were main contributions in the first principal component for conventional japonica rice while in the second principal component for hybrid indica rice. These results suggest that medium-chain FAs account for the decrease of seed vigor. Our study provides an important parameter for seed vigor testing and an early warning sign for seed storage of rice.