Submitted to: Rice Technical Working Group Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/22/2010
Publication Date: 2/22/2010
Citation: Huang, B., Yan, Z., Yan, W., Ntamatungiro, S. 2010. Genotypic differences in straighthead resistance of rice cultivars [abstract]. Rice Technical Working Group Meeting Proceedings. p. 85. Interpretive Summary:
Technical Abstract: Straighthead is one of the most important non-fungal diseases in U.S. rice production and the oldest rice disease in Arkansas since the 1900’s. When a highly susceptible variety is grown under conditions conducive to straighthead, grain yield losses can be significantly high. Reducing the impact of straighthead to rice will greatly increase grain yield and reduce rice production costs. Twelve cultivars and 20 new breeding strains were evaluated in a field experiment at the Agricultural Experiment Research Station of the University of Arkansas at Pine Bluff (UAPB) (Latitude: 34° 15' N, Longitude: 92° 01' W, Elevation: 232 feet) during the 2008 rice growing season. The study was planted on April 24, 2008 and was managed according to recommended practices. During the growing season, straighthead symptoms were observed on 11 cultivars and strains. Compared to straighthead-free rice cultivars and strains, grain yield of cultivars and strains affected by straighthead was greatly reduced. Six lines (PB-2, PB-12, PB-13, PB-17, PB-4, and PB-11) showed good tolerance to straighthead. There were significant differences (P < 0.001) in yields among these lines from the susceptible lines or cultivars. Four top strains (PB-2, PB-12, PB-13, and PB-17) had significantly higher yields than the control cultivar (Francis). They also showed very significant differences from two other CK cultivars (Wells and M202). The grain yields of these top 6 strains (PB-2, PB-12, PB-13, PB-17, PB-4, PB-11) were 9886, 9849, 9098, 7928, 7147, and 7141 Kg/ha, respectively. The grain setting rate of those cultivars and strains were 70.4%~87%. Our findings could indicate the presence of genetic variability among rice cultivars or strains, and may suggest a possibility for genetic improvement towards tolerance of straighthead in rice.