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ARS Home » Southeast Area » Stuttgart, Arkansas » Dale Bumpers National Rice Research Center » Research » Publications at this Location » Publication #285808
Title: Differential Responses of Breeding Strains to Straighthead

Author
item HUANG, BIHU - University Of Arkansas
item YAN, ZANGBU - University Of Arkansas
item Yan, Wengui

Submitted to: ASA-CSSA-SSSA Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/15/2012
Publication Date: 10/21/2012
Citation: Huang, B., Yan, Z., Yan, W. 2012. Differential Responses of Breeding Strains to Straighthead. ASA-CSSA-SSSA Proceedings. Oct. 21-24, 2012. Cincinnati, OH. pg. 239-15.

Interpretive Summary:

Technical Abstract: Straighthead disorder is an important non-fungal disease of rice in the U.S. When this occurs, grainfill in the panicle is dramatically reduced. When a highly susceptible cultivar is grown under conditions favorable for straighthead, yield losses can be up to 100%. Improving straighthead tolerance will greatly secure grain yield and reduce rice production costs. For unexplained reasons, straighthead symptoms are induced when arsenic based herbicides, like MSMA, are applied. As a result previous studies on straighthead have been conducted under conditions using arsenic chemicals in an effort to assure the potential for symptom development. However, evaluation of this disease under natural conditions would be practically important for cultivar improvement. Based on 2008 results of grain yield and straighthead rating, 12 lines including three commercial cultivars and nine breeding strains of long grain rice were selected for this study in a field having native, untreated soil. These lines were planted on three dates, 10 days apart in 2009, 2010 and 2011 on the farm of the University of Arkansas Pine Bluff (UAPB). Grain yields of the cultivars and strains were greatly reduced because of natural incidence of straighthead. Breeding strains PB-11 and PB-12 showed a high tolerance to straighthead consistently for the three years, indicated by a low rating of 1-2 for straighthead symptoms using a 1-9 scale where 1 had no and 9 had the most severe straighthead. Strain PB-2 showed fair tolerance with the scores ranging 3 to 5 in the three years. As a result, PB-11, PB-12 and PB-2 yielded significantly greater than the control cultivar Francis in three years (P<0.001). Francis is a widely used commercial cultivar and moderately susceptible to straighthead with a rating of 4-5. Straighthead performance of strain PB-13 was unstable among three years with a variation 1 – 7 for the scores. Consequently, its yield reduction increased along with an increase of its straighthead score each year. Our findings suggest that there is genetic variation for straighthead resistance that can be useful in coping with straighthead disease in rice production. Consistent performance of some strains for straighthead symptoms demonstrates the feasibility of establishing a native soil field site at the UAPB to evaluate straighthead disease directly for cultivar improvement.