Yuni Widyastuti
Balai Besar Penelitian Tanaman Padi Jl. Raya 9 Sukamandi, Subang 41256, Jawa Barat

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Perilaku Pembungaan Galur-galur Tetua Padi Hibrida Yuni Widyastuti; I. A. Rumanti; Satoto Satoto
Iptek Tanaman Pangan Vol 7, No 2 (2012): Desember 2012
Publisher : Puslitbang Tanaman Pangan

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Abstract

Rice (Oryza sativa L) is naturally a selfpollinated crop, although outcrossing rate of 0.5 to 6.8% had been observed in some genotipes. In hybrid rice breeding, outcrossing ability of parental lines is expected to increase seed set. The successful of hybrid rice seed production is affected by floral characteristics, synchronous of parental line flowering, and other morphological characters which affect pollen transfer from male parent (B or R line) to female parent (A line). Some rice agronomic characters such as number of productive tillers per hill, number of spikelets per panicle, plant height, narrow and short of flag leaf, also panicle exertion, could affect outcrossing rate. The floral characteristics of A line such as: stigma and stylus size, stigma exertion, stigma receptivity period, angle of floret, period of the spikelet opening, and panicle exerted above flag leaf, are also affecting the outcrossing rate. However, the flowering characteristic of male parent (B or R line) such as: anther size, filament length, number of pollen per anther, percentage of exerted anther and duration of spikelet opening, are also contributing to the rate of outcrossing. Study of heritability and genetic variability analysis revealed that all characters supporting outcrossing could be improved by breeding. The environmental factors that affect outcrossing in rice are temperature, relative humidity, light intensity, and wind speed.
Perbedaan Hasil Padi Antarmusim di Lahan Sawah Irigasi Satoto Satoto; Yuni Widyastuti; Untung Susanto; Made Jana Mejaya
Iptek Tanaman Pangan Vol 8, No 2 (2013): Desember 2013
Publisher : Puslitbang Tanaman Pangan

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Abstract

Indonesia as a tropical country, has two distinct planting seasons, i.e. rainy (WS, October-April) and dry season (DS, May-September). The difference between the two seasons include the amount of rainfall, air temperature, humidity, solar radiation, and cloudiness which cause yield gap between seasons. Rice yield testing at various locations and seasons using inbred and hybrid varieties showed the occurrence of yield gap patterns. In East Java during the 2001-2003 testing showed inconsistence yield gap between planting seasons across locations. Testing of 29 very early maturing accessions in Kuningan (550 m asl) during DS 2010 and WS 2010/2011 showed no significant yield gap between planting seasons. Similarly, testing of 10 GSR inbred lines along with four check varieties during DS 2012 and WS 2012/2013 showed no significant yield gap due to seasons, genotypes, and plant spacing. Factors which presumably affected the yield gap include air temperature, CO2 concentration, and solar radiation during grain filling period. Increasing temperature had reduced the grain yield, where as increasing CO2 concentration increased plant biomass formation, while optimum solar radiation during grain filling increased grain yield. To reduce yield gap between seasonal planting, the more readily observable causing the yield gap should be anticipated, such as: pests and diseases in each season for each location, assigning suitable variety for specific location and planting season, and application of most appropriate cultivation techniques for each location and season (fertilizers application, plant spacing, irrigation, and pest/diseases management).