Studies On Seedling Quality Of Hybrid Rice With Fuzzy Clustering Analysis

When the practitioners of agricultural technology guide the rice (Oryza sativa L.) production, they estimated the quality of the rice seedlings according to their phenotype. At present, because of the lack of quantitative criterion in morphological characters, visual estimation was often used in appraising the quality of rice seedlings. Due to the knowledge, technology and experience of the appraisers, due to the estimated environment and the compared objects, this kind of estimation was very subjective and blind. It was hard to make the right judgment on the quality of the rice seedlings so much so that the management was affected.In this experiment, the hybrid rice D-You 86 was seeded and transplanted in 16 different fields with different soil and fertilized level. Ten seedlings were selected at random from each field, numerated with signs and the morphological characters such as growth duration, the number of leaves, the number of tillers, the number of roots, the number of white roots, the width of the maximum leaf length, plant height, the length of erect leaf, the width of stem base are investigated and recorded respectively. Moreover, 5 rice culture experts are invited to judge the phenotype by visual estimation: flourishing seedlings, strong seedlings, normal seedlings and ebb seedlings. The generate root potential and the generate root ability were measured by water culture. The main results are as follows:1. The experimental result was statistically analyzed by fuzzy clustering analysis. The results showed that the rice seedlings can be clustered, and the fuzzy clustering picture can be drawn with the given interception, λ ∈ [0,1]. When λ was 0.555 with the practical experience of rice culture, the rice seedlings can be divided into 4 types, it was respectively corresponding to 4 kinds of phenotype that were judged by visual estimation, and the quantitative criterion in morphological characters of each kind of seedling was initially put forwarded.Type I included ten fields, strong seedling in visual estimation. The characters were medium leaf age, more green leave, more white roots, more tillers, higher seedling, and longer erect leaves, medium of width of the maximum leaf length, narrow base stem, stronger potential and ability of root developing. This kind of seedling is fit to rice cultivation in production and extended in future.