Straighthead disease is a physiological disorder in rice and the most widespread non-fungal disease of the U.S. straighthead greatly reduces rice yield. Straighthead studies were most conducted in the artificial field...Straighthead disease is a physiological disorder in rice and the most widespread non-fungal disease of the U.S. straighthead greatly reduces rice yield. Straighthead studies were most conducted in the artificial field which was Arsenic amendment plots due to the similarity of straighthead symptoms of Arsenic damage. To evaluate the straighthead disease resistance in natural condition, 46 rice lines, including 24 inbred lines and 22 hybrid combinations which were developed from breading program, were chosen for straighthead and agronomy characters testing in a native soil where straighthead naturally induced in the past years at University of Arkansas at Pine Bluff (UAPB), Arkansas in 2011 and 2012. The straighthead of rice were rated from 0 to 9 levels, and 0 was the least straighthead disorder and 9 was the most severe straighthead disorder. Cocodrie (CCDR) was used as the check in this study. The results of 2011 showed that the yields of 8 entries were higher than the check CCDR. The straighthead scores of these 8 entries were 0 - 1 which indicated their resistance to straighthead. The rest of the entries had lower yields than check CCDR with straighthead scores 5 - 6 which indicated their moderate susceptibility to straighthead. The yields were negatively related to the straighthead scores (r = -0.9178, P < 0.01). The results of 2012 showed that the yields of 9 hybrids and 6 inbred entries were higher than the check CCDR. The straighthead scores of top 12 entries were 0 - 2 which indicated that they were resistant to straighthead and 3 entries with straighthead score of 3 which indicated they were moderately resistant to straighthead. The rest 3 hybrids and 4 inbred entries had lower yields than the check and their straighthead scores were 5 - 6 which indicated their moderately susceptible to straighthead. The yields was negatively related to the straighthead scores (r = -0.956, P < 0.01). Compared to CCDR, the yield of hybrids showed their straighthead resistance at some extent. The yields of top six entries,展开更多
Yield test of 41 entries, 32 new hybrids, 8 male parents restore lines and 1 inbred variety, was conducted on the farm of University of Arkansas at Pine Bluff (UAPB) in 2012. The only inbred Francis in this experiment...Yield test of 41 entries, 32 new hybrids, 8 male parents restore lines and 1 inbred variety, was conducted on the farm of University of Arkansas at Pine Bluff (UAPB) in 2012. The only inbred Francis in this experiment was used as the check. Francis is a popular variety and widely used in Arkansas rice production. Results showed that the yields of 7 hybrids were 25.7% - 30.7% higher than check Francis. Hybrid 28s/BP23R had the highest yield, 10846.6 kg/hectare and over check by 30.7%. The yield of hybrid 28s/PB-24, was 10628.9 kg/hectare and over check by 28.1%. The yields of hybrid 28s/PB-22 and 33A/PB24 were 10549.8 and 10539.8 kg/hectare and over check by 27.1% and 27.0%, respectively. The sterile lines 28s, 29s, 30s and 33A have good combinability. PB2, PB5, PB12, PB22, PB23, PB24, and PB25 are good restorers and most of their hybrids were over check more than 17%. Sterile 28s has DEMG (Dominant Early Maturity Gene) which can make earlier heading hybrids by crossing with late restorer lines. Sterile 30s and 33A have no DEMG but have heat resistant gene. They can make late heading hybrids by crossing with late restorer lines PB24 and PB22 and the late heading hybrids can resistant to hot temperature. These results showed that these sterile lines, restorer lines and hybrids can be used in rice production of Arkansas in the future.展开更多
文摘Straighthead disease is a physiological disorder in rice and the most widespread non-fungal disease of the U.S. straighthead greatly reduces rice yield. Straighthead studies were most conducted in the artificial field which was Arsenic amendment plots due to the similarity of straighthead symptoms of Arsenic damage. To evaluate the straighthead disease resistance in natural condition, 46 rice lines, including 24 inbred lines and 22 hybrid combinations which were developed from breading program, were chosen for straighthead and agronomy characters testing in a native soil where straighthead naturally induced in the past years at University of Arkansas at Pine Bluff (UAPB), Arkansas in 2011 and 2012. The straighthead of rice were rated from 0 to 9 levels, and 0 was the least straighthead disorder and 9 was the most severe straighthead disorder. Cocodrie (CCDR) was used as the check in this study. The results of 2011 showed that the yields of 8 entries were higher than the check CCDR. The straighthead scores of these 8 entries were 0 - 1 which indicated their resistance to straighthead. The rest of the entries had lower yields than check CCDR with straighthead scores 5 - 6 which indicated their moderate susceptibility to straighthead. The yields were negatively related to the straighthead scores (r = -0.9178, P < 0.01). The results of 2012 showed that the yields of 9 hybrids and 6 inbred entries were higher than the check CCDR. The straighthead scores of top 12 entries were 0 - 2 which indicated that they were resistant to straighthead and 3 entries with straighthead score of 3 which indicated they were moderately resistant to straighthead. The rest 3 hybrids and 4 inbred entries had lower yields than the check and their straighthead scores were 5 - 6 which indicated their moderately susceptible to straighthead. The yields was negatively related to the straighthead scores (r = -0.956, P < 0.01). Compared to CCDR, the yield of hybrids showed their straighthead resistance at some extent. The yields of top six entries,
文摘Yield test of 41 entries, 32 new hybrids, 8 male parents restore lines and 1 inbred variety, was conducted on the farm of University of Arkansas at Pine Bluff (UAPB) in 2012. The only inbred Francis in this experiment was used as the check. Francis is a popular variety and widely used in Arkansas rice production. Results showed that the yields of 7 hybrids were 25.7% - 30.7% higher than check Francis. Hybrid 28s/BP23R had the highest yield, 10846.6 kg/hectare and over check by 30.7%. The yield of hybrid 28s/PB-24, was 10628.9 kg/hectare and over check by 28.1%. The yields of hybrid 28s/PB-22 and 33A/PB24 were 10549.8 and 10539.8 kg/hectare and over check by 27.1% and 27.0%, respectively. The sterile lines 28s, 29s, 30s and 33A have good combinability. PB2, PB5, PB12, PB22, PB23, PB24, and PB25 are good restorers and most of their hybrids were over check more than 17%. Sterile 28s has DEMG (Dominant Early Maturity Gene) which can make earlier heading hybrids by crossing with late restorer lines. Sterile 30s and 33A have no DEMG but have heat resistant gene. They can make late heading hybrids by crossing with late restorer lines PB24 and PB22 and the late heading hybrids can resistant to hot temperature. These results showed that these sterile lines, restorer lines and hybrids can be used in rice production of Arkansas in the future.
