Studies on floral variation in walnut (Juglans regia L.).

The type and character of floral organ variation in Juglans regia L.were observed,and the anatomy of hermaphroditic development was also analyzed through paraffin section.The 2 942 seedlings from cross combination were raised using 6 precocious forms,and 2 later mature forms.Among 2 648 seedlings from artificial cross by precocious forms and open pollination of precocious forms,20.34% of the seedlings were produced flowers in the third year.The 294 seedlings from later mature forms produced no flowers in the third years.Twelve seedlings of the 538 precocious cross seedlings were observed on floral organ variations.The variation types including hermaphrodite flower,spike inflorescence,branch spike inflorescence,male and female flowers in one spike inflorescence,stigma variation,rosette female inflorescences.The study on floral organ variation was kept from 2003 to 2008.Stable inheritance of floral organ variation only appeared in C3 cross seedling from Xin 1×Xiangling.The floral organ variation was found in adventitious shoots of Xiangling cultivar.The anatomy of hermaphrodite flower development procedure was:Inflorescence primordium-flower primordium-bract primordium stamen primordium-stigma primordium-ovary primordium.The floral organ variation only took place in the second shoots and flowers.The walnut with floral organ variation is a valuable material to study the earlier fruiting character and the floral organ development of walnut.