对种植于南京的薄壳山核桃[Carya illinoensis (Wangench.) K. Koch]18 个品种(系)的开花物候期(包括雌花和雄花的单花开花过程和花期以及雄花散粉期和雌花可授期)进行了观察和比较。结果表明:供试的18 个品种(系)雄花单花的开放过程包括花被裂开、雄花变黄、花药散粉、花药变黑和小花脱落5 个时期,其开放过程持续天数为13 ~22 d;各品种(系)雄花集中在4 月下旬进入初花期,5 月中下旬进入落花末期,雄花的整个花期持续天数为16 ~24 d。雌花单花的开放过程包括子房显露、柱头裂开、柱头倒“八”字形、柱头枯萎和子房膨大5 个时期,其开放过程持续14 ~22 d;雌花集中在4 月下旬进入初花期,末花期集中在5 月中旬,雌花的整个花期持续天数为12 ~23 d。18 个品种(系)的雌花可授期天数为3 ~10 d、雄花散粉期天数为4 ~9 d,多数品种(系)的雄花散粉期与雌花可授期天数为7 d。依据雌花和雄花开放的先后顺序可以确定其中的12 个品种(系)为雌先型,5 个品种为雄先型,仅1 个品种为同时型;并根据观察结果确定了22 个可行的授粉组合。适宜的品种配置方案为‘马罕’(‘Mahan’)、‘西奥克斯’(‘Sioux’)、‘金华’(‘Jinhua’)、‘卡多’(‘Caddo’)和‘波尼’(‘Pawnee’)。

Flowering phenology (including blossom process of single flower and flowering period of male and female flowers, pollen shedding stage of male flower and receptivity stage of female flower) of eighteen cultivars (strain) of Carya illinoensis (Wangench.) K. Koch planted in Nanjing was observed and compared. The results show that blossom process of male single flower of eighteen cultivars (strain) includes five stages of perianth dehiscence, male flower turning yellow, anther shedding pollen, anther turning black and floret falling off, lasting days of blossom process of male flower are 13-22 d; most male flowers of all cultivars (strain) enter into the early flowering stage at the last of April and enter into the late stage of flower dropping at the middle and last of May, and lasting days of the whole flowering period of male flower are 16-24 d. Blossom process of female single flower of eighteen cultivars (strain) also includes five stages of ovary appearing, stigma dehiscence, stigma inverse-eight-shape, stigma withering and ovary enlargement, its lasting days are 14-22 d; most female flowers of all cultivars (strain) enter into the early flowering stage at the last of April and enter into the final flowering stage at the middle of May, and lasting days of the whole flowering period of female flower are 12-23 d. Days of receptivity stage of female flower of eighteen cultivars (strain) are 3-10 d and those of pollen shedding stage of male flower are 4-9 d, those of pollen shedding stage of male flower and receptivity stage of female flower for most cultivars (strain) are 7 d. According to the time order of blossom of male and female flowers, twelve cultivars (strain) could be determined to protogynous type, five cultivars protandrous type and only one cultivar homogamy type; twenty-two feasible pollination combinations could be selected according to these observation results. The appropriate configuration scheme of cultivars is ‘Mahan’, ‘Sioux’, ‘Jinhua’, ‘Caddo’and ‘Pawnee’.