摘要 : The study was conducted to observe the bitter pit incidence in relation with cultivars, rootstocks, minerals content in leaves and fruits under commercial orchard conditions, and to examine the accompanying anatomical changes. Num... 展开 The study was conducted to observe the bitter pit incidence in relation with cultivars, rootstocks, minerals content in leaves and fruits under commercial orchard conditions, and to examine the accompanying anatomical changes. Number of pits countedat harvest was high in 'Megumi', medium in 'Jonagold' and 'Golden Delicious', and low in 'Mutsu', 'Fuji', and 'Starkrimson'. The pit was the deepest in 'Fuji', More pits were observed in the half to the calyx end of a fruit than in the stem end part in all the cultivars investigated. Epidermal and cuticular layers of the pitted areas disappeared due to destruction of the cells, and the flesh cell underneath were collapsed in the 'Jonagold' and 'Fuji', Numerous starch grains were found in 'Starkrimson',not like in the forme layers consisting of small cells were newly formed to fill the disappeared epiderma and cuticular layers, and in such less starch grains were observed in a shallower depth. Symptoms in the former and the latter are thus understood to be typical of bitterpits and cork spots, respectively. 'Fuji' grafted on M26 showed much less incidence than the same cultivar grafted on MM 106, implying a great effect graft on rootstock on the symptom incidence of rootstock, A significant differencein N, K, and Ca content with N/Ca and K/Ca was more noted in flesh than in fruit skin and fruit core. Thus, it is reasonable to analyse mineral contents of flesh for diagnosis of pitted fruit. Pitted ftuit was significantly lower in flesh Ca content ascompared with non-pitted one, while N and K contents were tended to be higher. On the contrary, N/Ca and K/Ca were significantly higher in pitted fruit than non-pitted ftuit. In terms of bitter pit development related to flesh mineral content, N/Ca and K/Ca should be more important than flesh N and Ca content in the same cultivar, while genetic influence is more remarkable than mineral ones among other cultivars. 收起