Studies on Optimum Cultivation Methods for Seed Production of Rice Cultivars with Short Panicles

DOI IR JASI Web Site

Bibliographic Information

Other Title
  • 短穂飼料用イネ品種の効率的種子生産方法の検討
  • タンスイ シリョウヨウ イネ ヒンシュ ノ コウリツテキ シュシ セイサン ホウホウ ノ ケントウ

Search this article

Description

'Tachisuzuka' and 'Tachiayaka', which are promising new rice cultivars with short panicles, have been developed for whole crop silage (WCS) use. They offer improved lodging resistance, harvesting period, straw yield, sugar content, silage fermentation and feed value due to their morphological characteristics, which result from their short panicle (sp1) mutant gene. However, there is a problem in that their seed production is poor. We investigated a way of increasing the seed yields of these cultivars by optimizing their cultivation methods. In this study, we applied factorial design or fractional factorial design to the design and analysis of experiments whose aim was to evaluate the factors affecting seed production in short-panicle cultivars. We investigated four (in 2010) and five (in 2011) factors including planting time, planting density and fertilization methods, each at two levels, for two (in 2010) and four (in 2011) cultivars. The panicles of 'Tachisuzuka' varied greatly in size according to the treatment. In the short-panicle cultivars, there was a strong positive correlation between seed yield and panicle size, and no correlation between seed yield and panicle number. This is in contrast to wild-type panicle cultivars, which usually exhibit a positive correlation between yield and panicle number. Factors related to planting time and fertilization method had a strong effect on seed yield with 'Tachisuzuka'. For a high yield with 'Tachisuzuka', late planting and no nitrogen application until topdressing is applied at the panicle formation stage are recommended. The expected seed yield with the treatment was 409g/m^2. We obtained a seed yield of 420kg/10a for 'Tachisuzuka' using the optimized cultivation method in a demonstration field in 2011. On the other hand, we never achieved a satisfactory result with 'Tachiayaka'. 'Tachiayaka' is another short-panicle cultivar with an sp1 mutant gene, but with different heading characteristics from 'Tachisuzuka'. Further studies are required to obtain a comprehensive understanding of the function of the sp1 gene in rice cultivars with short panicles.

Journal

Keywords

Details 詳細情報について

Report a problem

Back to top