Physiological responses were studied in temperature-controlled glass house at Okinawa, Japan to evaluate drought and high temperature resistances of cowpea cultivar/strains for Sahel, Africa. Four drought-tolerant cow...Physiological responses were studied in temperature-controlled glass house at Okinawa, Japan to evaluate drought and high temperature resistances of cowpea cultivar/strains for Sahel, Africa. Four drought-tolerant cowpea cultivar/strains （cv. TVu-11986; TVu-11979; IT-96D-604 and Dan Ilia）, and three sensible strains （cv. IT96K-238-3, IT96K-231-1 and TVu-7778） were grown in pots and imposed to drought （soil content; 9.7±1.9%（w/w））, high （30/26℃, day/night, 12/12 hour）, normal （27/23℃, control） and low （24/20℃） temperature conditions after flowering. Plant fresh weight reduced 80%, 26% and 1% by dry, high and low temperature, respectively. Stem diameter decreased 32% and 2% by dry and low temperature, respectively, but increased 5% by high temperature. Difference between the drought tolerant and sensible cultivars/strains, pre-evaluated by IITA, was explained by relationship between stem diameter and plant fresh weight with 77% of reliability. The 35% of misclassification were due to misjudgment of drought tolerant as sensible in dry plot. The stem diameter highly correlated with all parts of plant weight in all regimes except in dry treatment. Difference of the classification between IITA and our results may cause different survival strategy against drought. The cultivars/strains, evaluated as drought tolerant by IITA, might fatten up at early stage, and could avoid from drought at latter growing stage.展开更多
文摘Physiological responses were studied in temperature-controlled glass house at Okinawa, Japan to evaluate drought and high temperature resistances of cowpea cultivar/strains for Sahel, Africa. Four drought-tolerant cowpea cultivar/strains （cv. TVu-11986; TVu-11979; IT-96D-604 and Dan Ilia）, and three sensible strains （cv. IT96K-238-3, IT96K-231-1 and TVu-7778） were grown in pots and imposed to drought （soil content; 9.7±1.9%（w/w））, high （30/26℃, day/night, 12/12 hour）, normal （27/23℃, control） and low （24/20℃） temperature conditions after flowering. Plant fresh weight reduced 80%, 26% and 1% by dry, high and low temperature, respectively. Stem diameter decreased 32% and 2% by dry and low temperature, respectively, but increased 5% by high temperature. Difference between the drought tolerant and sensible cultivars/strains, pre-evaluated by IITA, was explained by relationship between stem diameter and plant fresh weight with 77% of reliability. The 35% of misclassification were due to misjudgment of drought tolerant as sensible in dry plot. The stem diameter highly correlated with all parts of plant weight in all regimes except in dry treatment. Difference of the classification between IITA and our results may cause different survival strategy against drought. The cultivars/strains, evaluated as drought tolerant by IITA, might fatten up at early stage, and could avoid from drought at latter growing stage.
