Study On The Relation Of Various Cultivars Pollination,Fruit Set Rate And Its Internal Hormone In Pear (Pyrus L.)

The paper used sixteen pear cultivars as materials, these cultivars including Huangjin, Shinseiki, Xinggao, Ya pear et al which mainly planted in production. We investigated some internal factors effecting their pollination and fertilization, these factors included pollen quantity, pollen germination percentage, seed-setting , plant internal hormone and so on. The results as follows:1) Through studies on pollen quantity, pollen germination percentage and seed-setting of these sixteen cultivars. Results: pollen quantities of Kohsui, Shinseiki, Meirensu et al were high; pollen quantities of Ya pear, Zaomeisu, China pear 1 et al were middle; pollen quantities of Bayuesu, Shinseiki, Hongtaiyang were lowest. At optimum liquid culture medium composed of 10% sucrose, pollen germination percentages of Meirensu , Shinseiki, Ya pear were 70%, that of Shinseiki was the lowest, only 30.0%; seed-settings of Zaomeisu, Qiyuesu, China pear 1 were very high, but those of the others were lower when they were self-pollination and fertilization; seed-settings were all more 70% when they pollinated between varieties.2) We studied pollen germination percentage , florescence research, self-compatibility and cross-compatibility among Zaomeisu, China pear 1 , Qiyuesu et al which relation was near. The results suggest: the three culturals's pollen germination percentage were more than 60% 4 h after cultured in liquid culture medium composed 10% sucrose, 24℃; Florescence most concentrated April third-tenth (2003); For Zaomeisu and Qiyuesu ,their anthotaxy and flower self setting fruit percentage were more than 90%,except for China pear 1, anthotaxy self setting fruit percentage was 48.3%, flower self setting fruit percentage was 33.1%; Their cross-compatibility was higher, anthotaxy and flower self setting fruit percentage almost reached 100%, the lowest also reached 94.9%, but last self-compatible gathering fruit percentage was lower comparatively and fruit average seed numbers were lower, while cross-compatible gathering fruit percentage and fruit average seed numbers were closed to that of nature pollination. It was obvious that closed pear relation did not affect pollination and fertilization between Zaomeisu, China pear 1,Qiyuesu et al, it was to say that cross-compatibility between them was high.3) We groped a set of gas chromatography system which had simple process , convenient manipulation, high precision and was fit for determining the content of IAA and ABA in pear young fruits. This settled base of studies on changing rule of hormone content in pear pistil tissue and young fruits after pollination and fertilization.4)We used gas chromatography to study the quantity of IAA and ABA in pear young fruits of different varieties from self-pollination to first physiological fruit-falling period. The results were following: For Self-incompatible cultivars such as Ya pear, Dangshansu, Changshou and self-compatible cultivars such as Qiyuesu, Zaomeisu, the changing rule of IAA content in young fruits showed different from self-pollination to physiological fruit-falling period. But the trend of ABA content between compatible and incompatible cultivars, 24 h-72 h after self-pollination, was different; while that, from 72 h after self-pollination to first physiological fruit-falling period, showed the same changing rule. These results suggested that internal hormone content and balance of pistil tissue and young fruits might be related with final effect of pollination and fertilization after self-pollination among different pear culturals.