Abstract: Canopy temperature depression( CTD) has been proposed as the best predictor for evaluating wheat yield performance, but the metabolic difference between strong gluten type wheat and medium gluten type wheat has seldom been addressed.Our objectives were to evaluate the CTD diversity of two gluten types and to determine optimal measurement times for selecting wheat varieties in the Northern of Yellow ＆ Huai Facultative Winter Wheat Region.Twenty-eight strong gluten wheats and twenty-seven medium gluten wheats were grown in randomized complete blocks with 3 replicates in plots of 6.0 m² ( 6 rows,0.20 m apart).Canopy and air temperatures were measured at heading date, anthesis,7 d after anthesis, 14 d after anthesis, 21 d after anthesis, and 28 d after anthesis under irrigation, respectively.Six CTDs measured from heading time to end milk grain stage were indicated highly significant differences between strong gluten type wheat and medium gluten type wheat.Mean CTD at 21d after anthesis for medium gluten type wheat was only significantly positively correlated with grain yield( r = 0.417 5,P< 0.001) and thousand kernel weight( r =0.526 3,P< 0.001).In additive,we found CTD has been associated with yield increase among medium gluten wheat cultivars because of as an indicator of heavy kernel weight since CTD is related to cumulative transpiration.The principal component analysis was effective in that the first three principal components could together accounted for 51.72% and 63.45% of the total variation of the strong gluten type and the medium gluten type, respectively.Especially,CTD at 21 d after anthesis was the most important trait contributing to variation that explained about 16.91% and 36.95% of the total regional variance for the strong gluten type and the medium gluten type, respectively.The significant difference of CTD at 21 d after anthesis was consisting with grain yield.Furthermore, five strong gluten cultivars, involving Jinan 17,Lu 0540258,Lu 0540261,Lu 056479 and Lu 0540252, and five medium gluten cultivars, involving Jimai 22,Lu055359,Lu 055282,Lu 0540319 and Lu 055293,were selected according to the factor scores, all of which were more obvious difference of CTD and higher grain yield．

Key words: Winter wheat( Triticum aestivum L． ), Canopy temperature depression, Strong gluten type, Medium gluten type, Yield traits

CLC Number: 

• S512.1

• S311