结球芥菜的生长动态与叶球形成

The Growth and Leaf Head Formation in Brassica juncea var. capitata Bailey

结球芥菜自播种至叶球采收可分为发芽、幼苗、叶簇生长和叶球形成4个生长期.植株、根、外叶和叶球的鲜样质量和干样质量随生长进程均逐步增加,呈单峰曲线的增长动态.叶球的鲜样质量和干样质量分别占植株鲜样质量和干样质量的48.2%和48.8%,经济系数近0.5.生育过程中,第1～5展叶是培育幼苗和叶簇的功能叶,第5～9展叶则是叶球形成的主要功能叶.叶球形成过程中球叶数及其叶面积和质量均逐步增加,采收时叶球约有12片球叶.球叶的叶面积和质量都由外而内逐渐减少,叶球的大小和质量主要决定于最外面的6片球叶(占球叶面积的84%和叶球质量的85%),属叶重型叶球.

There were four stages （germination, seedling, leaf growth and leaf head formation） during head mustard growth from sowing to harvest. The fresh and dry weight of top plant, root, outer leaf and leaf head increased gradually, following a single-peak curve. The fresh weights of leaf head was 48.2% of total plant fresh weight. The 1st-5th expanded leaves played important role in seedling and leaves growth, and 5th-9th expanded leaves played important role in leaf head formation. There were twelve inner leaves at harvesting time. Single leaf area and weight decreased gradually from outside to inside. The size and weight of leaf head were determined by outer six head leaves which accounted for 84% leaf area and 85% weight of leaf head.