特大粒甘蓝型油菜籽粒和角果发育形态特征

为进一步了解特大粒甘蓝型油菜种质DL01的大粒机理，以普通籽粒H8为对照，田间调查并比较分析它们的生育期、主花序角果和籽粒在形态、重量、灌浆速率和相对含水量等特征及变化。结果表明，特大籽粒DL01的平均全生育期为207d，比H8长17d，尤其是灌浆期长12d以上；在开花当天，DL01的花梗直径、子房的长度和宽度及重量分别是H8的1.30、1.21、1.39、1.46倍；其最大角果皮光合面积和角果鲜重分别是H8的2.2和3.0倍；单荚胚珠数二者相当，但DL01的着粒数比H8少，最大差异为64%；DL01最大籽粒鲜重（百粒重1.20g）、干重、体积和灌浆速率均是H8的2倍；在含水量方面，在荚角成熟前DL01的果皮含水量比H8略高（3%～5%），但H8荚果高含水量（〉75%）期只能维持68d，而DL01荚果高含水量（〉80%）期可维持80d；H8籽粒鲜重在47d时达到最高，其含水量为52%，DL01籽粒鲜重在62d时达到最高，其含水量为50%。因此结论是，DL01大粒源自大子房、粗花梗、大的角果皮表面积、低着粒数、高的果皮与籽粒含水量并且灌浆持续时间较长。

Morphology and silique development of extra - large seed line DLO 1 of Brassica napus

To understand the extra-large seed characteristics of Brassica napus var DL01, silique traits were investigated in field on growth period, using normal seed line C001 as control. Results showed that DL01 average growth period was 207d, which was ～17d longer than C001. Grain filling period was 12d longer. Stalk diameter as well as ovary length, width and weight were 1.30, 1.21, 1.39 and 1.46 folds of C001 respectively at the first day of flowering. 100 seed weight （1.20g） and volume, as well as filling rate were 2 fold. The maximum photosynthesis areas of silique pericarp and fresh weight of siliques were 2.2 and 3.0 fold respectively. But their embryo number per silique were similar, and seeds per silique could be 64% less than C001. Moisture content （MC）, the peel MC was 3-5% higher, and the period of high MC （〉80%） lasted 80 days, while the period of high MC （〉75%） in C001 lasted only 68 days. The seed fresh weight of DL01 and C001 reached the peak at the 62nd and 47th day, with 50% and 52% MC respectively. In conclusion, the extra size of DL01 resulted from large ovary, thick stalk, and wide silique surface, as well as fewer grain number, higher MC of seed and silique, and longer filling duration.