Studies On Agronomictra And The Establishment Of Tissue Culture Regeneration System Of An Early Strain Of Lotus

An early strain of Lotus (Lotus corniculatus L.) is a new strain which bred by selection from Mirabal (Lotus corniculatus L.cv.Mirabal).The thesis studied on the growth,producibility and tissue culture regeneration system of the early strain of Lotus in order to set a good base for the application of other technologies and gene transform in the future. The main results are as follows:1 The early strain of Lotus grows well and can live through winter safely in Jingtai area. Though the new strain is from Mirabal, its growth period (92 days) is observably shorter than that of the original colony of Mirabal (110 days). And the seed maturity (19/7) is earlier about 26days than that of the original variety Mirabel (16/8)planted at the same time, this made a possibility that to get seeds twice in one year in warm area. At the stage of full bloom of the new strain colony, the average plant height of it is 40.20cm,the branches of it is 68.85 and the number of florets is 7.15.2 The analysis of grass group structure of the early strain showed that the amount of leaves of the new strain converged on the central part of the plant. The yields of hay,fresh grass and seeds of the new strain are all higher than that of the original colony of Mirabal through variance analysis, the average yield of fresh grass per year is 42.593t/hm2,the hay is 10.553 t/hm2, and the seed is 658.3kg/ hm2.At the initial flowering stage, the content of crude protein in the plant is 23.90%; the Dynamic change of the yields of every growth period and nutrient substances showed that the best time to use is at the squaring stage to the initial flowering stage, because higher yields and better quality of the new strain can be gained at this time.3 The experiment of the establishment of tissue culture regeneration system showed that the best inducing culture medium for callus of Lotus is MS+2,4-D1.5 mg·L-1+KT0.5 mg·L-1+ sugar 30g·L-1, and the induction rate is above 80%. The explants come from different parts would have different results in producing callus. It is better in using stockier stem apex and cotyledons as explants for inducing callus, and the induction rate reaches 84.6%～87.4%. The concentration of hormone and sugar has a great impact on the wound curing rate of the callus of Lotus. When the induced callus was put into the differentiated culture medium of MS+NAA0.1 mg·L-1+6-BA1 mg·L-1, it can differentiate adventitious buds, and when the concentration of sugar is at 20 g·L-1, there is most cluster living buds. And the optimum culture for inducing root is MS+NAA0.05mg·L-1,under the condition, more roots would be taken at a high speed, and it is also good for the hardening and transplanting of the seeding.