Improving germination, seedling establishment and biochemical characters of aged hybrid rice seed by priming with KNO3 + PVA

Using naturally aged F1 seed and artificially aged F1 seed of hybrid rice cultivar "Shan-you 63" as materials, 20 traits (10 traits measured in laboratory and 10 traits measured in paddy field) were compared between primed seed and corresponding control (non-primed seed). Results showed that germination percentage increased by 11.7% for naturally aged F1 seed after primed with 0.5% PVA (polyvinyl alcohol) + 1.0% KNO3 and by 10.3% for artificially aged F1 seed after treated with 1.0% PVA+ 1.0%KN03. Germination energy and vigor index of primed seeds were significantly enhanced. Activities of SOD, POD and CAT of primed seeds were significantly increased. Content of MDA and soluble sugar in seed leakage of primed seeds were significantly decreased. Compared with corresponding non-primed seeds, seedling establishment rate, seedling height and seedling weight significantly increased, and mean emergence time shortened obviously on-farm in 2006 and in 2007 in primed seeds. Under transplanting condition, there was no significant difference between primed seed and non-primed seed in plant height, panicle number per plant, panicle length, panicle weight and grain yield.