ISHS Acta Horticulturae 402: International Symposium on Cultivar Improvement of Horticultural Crops. Part 1: Vegetable Crops
THE MORPHOLOGY AND FUNCTION OF FLORAL ORGANS FOR CYTOPLASMIC MALE-STERILE LINE OF TUBER MUSTARD |
| Authors: | C. Zhujun, W. Bingliang, G. Qikang, D. Weimin, Z. Mingfang, H. Suqing, W. Genliang |
| Keywords: | tuber mustard, Cytoplasmic male-sterility Carpellatelization of anthers, Pollen grains with free of outer wall, Ability of self-fruiting, Ferility degree of pistil, Nectary |
| Abstract:
The F1 generation of Brassica juncea Coss. X Brassica campestris ssp. pekinensis L. with cytoplasmic male-sterility (CMS) was taken as the maternal parent and back-crossed with tuber mustard (Brassica juncea Coss. var. tumida Tsen et Lee.) as the recurrent parents up to the backcross generation BC6. Examination was made of the BC6 plants with rspect to the morphology of its floral organs and the sexual function of its pistil and stamens. One of the features of BC6 was the polymorphism of its floral parts as shown by the three distinct forms of the corolla among individual flowers: closed form, partial spread form and fully spread form. Each flower possessed a single column- or croo-shaped pistil, which was normal or heterostylic. Petals of the flower were mostly 4 in number and possessed 2.8 nectarines on average (ranging from 0 to 8). Growth index of the nectarines was estimated to be 0.76(n=1 100). The pistil and anthers of BC6 were separate from each other, or agglutinative (with anthers adhering to ovary), or holding out against each other (with the forepoint of anthers against the stigma). Each BC6 flower contains 1–11 (5.50 on the average) stamen, which may lack anthers or degenerate into sili-, petaloid- or pinnatelike form. Some silk-like anthers have saccate bulge on them. Pinnate anthers and some petaloid anthers are carpellatelized to form papilla and external ovules. A minor proportion of pollen grains produced were devoid of outer walls and were found to have a viability of only 2.0–5.5%. They were incapable of self fruiting as evidenced by experiments in which the flowers were bagged or the plants were isolated in a net house. Each siliquae bore 10.50 and 12.39 seeds after manual and natural pollination respectively. The classification of phenotypes for tuber mustard CMs-line and the potential breeding value of CMS were discussed. | |
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