Die Ährenatmung in der Phase der Kornfüllung bei Weizen (Triticum aestivum L.)

Abstract

Summary The respiration rate of attached ears of eight varieties of wheat was measured during grain development by means of an infrared gasanalyzer. The rates increased rapidly after flowering and reached a maximum value 8–10 days later. In the following period ear respiration decreased continuously. Dry matter increase of the grains was not synchronous to the time course of the ear respiration rates. During the maximum stage of respiration dry matter increase of grains is still low. Respiration rates of fertile and pollensterile ears of the same variety were compared during the whole phase of grain development. Their were also measured the rates of intact ears and ears deprived of kernels. From the results it was concluded, that the grains contribute about 40 % to the respiration of the whole ear. Comparing the theoretical value of respiration, necessary for biosynthesis of grain dry matter, it is concluded that the contribution of grain respiration to the respiration of the whole ear varies between 30 and 50 % in the genotypes investigated. There are differences between genotypes in relation to the coefficient, calculated from all respired CO 2 in the grain filling stage and the grain weight per ear.