桑樹の耐雪性に関する研究 : 第2報 強,弱品種の交雑F₁実生での生理特性の分離について

抄録

Previously, author reported that the ratios of insoluble carbohydrate content to total sugar content in living barks was higher in resistant varietes than succeptible ones at the time after the fall of leaves. This result seemed to be very interesting for the studies 'of the physiological mechanisms of blight resistance and breeding of the resistant strains. In present segregating studies pattern of this characteristic of Fl hybrids in 8 crosses between resistant varieties and succeptible ones were investigated. These results obtained were summerized as follows. ( 1 ) Parental varieties of all crosses (except one cross) showed the parallel results ivith previous finding. ( 2 ) Hybrid indiuiduals in each cross contained various of carbohydrate composition. And those indicated continious distribution, having peaks in mid parents. ( 3 ) Hybrid individuals in two crosses between cultivated and wild, the correlation between the degrees of resistance from field test and physiological characteristics has been shown as the same as observed between varieties in one cross, but not in another. Thus, to secure a clear conclusion in this problem, further investigations are necessary with in many crosses and a large number of hybrids.