甜菜个体发育规律的研究

Study on the Ontogeny of Sugar Beet

根据甜菜叶、根生长及糖分积累特点,将甜菜个体发育过程划分为苗期、叶丛形成期、块根增长期及糖分积累期等4个生育时期;甜菜一生中形成70余片叶,以叶丛形成期发叶最快,每1.5日生1片叶。11—30片叶寿命长,达75—80天。这20片叶对产量贡献大,称为基本功能叶;光合势以块根增长期最高,600dm~2/株·日以上:7月21日CGRt=CGRr、可将CGRt与CGRr曲线交叉时期,作为叶、根生长中心转移依据:块根增长期以前,干物质分配以叶部为主,占总干物重60%以上,其后根部占优势,至9月末达61.2%,生育中期糖分积累缓慢,后期积累快;7月20日左右,甜菜生长中心由叶部转至根部,8月末由根部转入糖分积累。

The ontogeny of sugar beet is divided into 4 stages of seedling growth rossette formation,tuber growth and sugar accumulation based on the ch- aractteristics of leaf and root growth as well as sugar accumulation.In the life of sugar beet,more than 70 leaves are formed and leaves formation proceeds most rapidly the rossette stage,with one leaf formed in every 1.5 days.Longevity of the 11st-30th leaves is 75—80 days.These 20 leaves make important contribution to the yield of sugar beet and are basic functional leaves.The photosynthetic potential is the highest,600 dm~2/ plant·day,at the tuber growth stage.On July 21,when CGRt is equal to CGRr,the crossing of CGRt and CGRr curves may be regarded as the evidence of the transfer of growth from leaf to tuber.Before the tuber growth stage,more than 60% dry matters are distributed mainly in leaves. However,larger portion of dry matters are translocated to the tuber at later stages which consists of 61.2% of the total at the end of september