Adding value to rice: improving temperate japonicas for tropical cultivation
2008
Yap, J.K. | Lee, K.S., International Rice Research Inst., DAPO Box 7777, Metro Manila (Philippines) | Hwang, H.G. | Kim, H.Y., National Inst. of Crop Science (NICS), RDA (Korea)
Temperate japonicas are known for their excellent grain characteristics and palatability. This characteristic makes them highly valuable in terms of economic value in relation makes them important in sustaining productivity in rice farming systems of the tropical countries. High value rice such as japonicas also stabilizes rice production because it motivate farmers to patronize rice farming especially in marginal areas where high yield is unattainable. However, japonicas are not suitable for tropical cultivation due to their inherent photo sensitivity in the tropics. Generally, their yield is less than 2 tons/ha, flowers as early as 26 DAS due to photo sensitivity and they are susceptible to major tropical insect pests and diseases. Through breeding efforts, improvements in yield were attained from the crosses of the original temperate japonica materials. Currently, yield of breeding lines ranges from 4.2 to 7.5 and 3.4 to 6.9 ton/ha during dry and wet season respectively. Flowering time improved to 70-90 DAS and resistance to bacterial blight, blast, and brown plant hopper were incorporated to most elite lines. Further effort to improve the yield potential and related biotic and abiotic resistance of current elite lines is continually made as well as effort to introduce genetic variability for future breeding needs.
显示更多 [+] 显示较少 [-]