Relationships Between Leaf Photosynthetic Characteristics And Yield, Quality Of Different Malting Barley Cultivars

The experiment was carried out at the breeding experimental station of Gansu Academy of Agricultural Sciences,in Huangyang Urban,Wuwei city,Gansu Province. Choosing over twenty springness malting barley which was cultivated in Europe and America and domestic springness malting barley(Ganpi) which was cultivated in Northwest China,using the methods by combination of field test and laboratory,to comparative study the relationship between changes of photophysiological characters and yield, quality of different malting barley cultivars,the results showed as following:1.In whole growth stage, Pn (photosynthetic rate) of thirty malting barley cultivars showed a single peak, and reaching their peak from heading, flowering stages to early filling stage.From booting stage to later filling stage, Pn (photosynthetic rate) average of malting barley was very significant(P<0.01),Pn average order of all genotype malting barley were 7.16,11.66,13.20,7.07,4.22μmol·m-2·s-1,corresponding coefficient of cariation were 5.09%,4.38%,7.46%,18.43% and 18.91%, Pn of different malting barley cultivars appeared high differentiation at different growth stage with growing process promoting and photosynthetic organs developing of malting barley. Pn of M-22,SCARLETT, Ganpi 4, Pasadena,MERIT,Z090M066M et al two-rowed barley were all higher, Pn of SCARLETT was maximum, it's value was 8.63μmol·m-2·s-1. B1614,6B98-9339 six-rowed barley had relatively high Pn at heading, flowering stages to filling stage.Tr (transpiration rate )increased with growing process promoting, its maximum appeared pre and post early filling stage, Tr decreased with function decline of leaves at middle, later filling stage. The difference of different malting barley cultivars increased from heading to flowering, and the difference of Tr was very significant (P<0.01) at whole filling stage. Tr of ROXANA two-rowed barley was maximum, its average was 3.22μmol·m-2·s-1, change of Tr of G231M004M,TRADITION,B1614,6B98-9339 six-rowed barley was relatively high.Gs(stomatal conductance)of different malting barley cultivars also showed the regularity of low-high-low, the difference of Gs was very significant (P<0.01) from jointing stage. Gs of KH DAMA,KH LEDI,SCARLETT,Ganpi4,6B98-9339 were high at different growth stage,but Gs of Jaxana, Qinta,Jubelete,TABORA were relatively bad, Gs was lowest, it was possible related with the adaptability of climate and environment in Northwest China.2.There was a positive correlation between LAI and yield of different malting barley cultivars. From jointing stage to later filling stage, the correlation between LAI and yield was very significant. LAI of thirty malting barley cultivars showed obvious difference,LAI of M-22,KH LEDI,Pasadena,Z014J081J,MERIT,Z090M066M et al two-rowed barley were all high.3.There was a positive correlation between Pn (photosynthetic rate)and yield of different malting barley cultivars.The correlation between Pn and yield was very significant (r= 0.5024 , 0.5359 , 0.6758) at booting, heading to flowering and later filling stage.4. By grey relational analysis, the relating sequence of different trait and yield were:1000 grain weight>plant high>spike number>grain number,thus,improving 1000 grain weight was the main key,meanwhile improving plant high,spike number, grain number.5. By grey relational analysis, the relating sequence of grain protein were:1000 grain weight, germination rate, germinating energy, screening rate. 1000 grain weight was≥38.00, germination rate and germinating energy were≥95% and≥90%, screening rate was≥75%, grain protein was≤12.5, they all measured up to first grade indexes,traits of most malting barley cultivars measured up to quality indexes.6. By grey relational analysis between Pn and yield, grain quality, from flag leaf stage to heading to flowering, Pn had important influence on yield and quality of malting barley,but the importance of Pn was gradually weakened at filling stage.7.By comprehensive comparison, photosynthetic characteristics of MERIT and Z090M066M were good,yield were also high,and malting barley cultivars with low grain protein could be used as the main malting barley cultivars which could be planted in Northwest China large scale. In addition, M-22,KH DAMA,KH LEDI, SCARLETT,Pasadena and Z014J081J were the reserve new malting barley cultivars with"high yield, high quality".