Compare On Technique Of Making Chromosome And Karyotype Analysis In Two Kinds Of Rhododendron

Rhododendron franch is under the Sect ponticum and Subsect Fortumes, the different of Rhododendron franch and Rhododendron lanatum is that Rhododendron lanatum is not only under the Sect ponticum,but it also under the Subsect. Lanata Chamb. At present, the field of study karyotype analysis that about two kinds of Rhododendron simsii Planch is a blank, at home and abroad. This article mainly carried out preliminary studies on the number and the relative length of chromosomes, and chromosome production technology that suitable for two rhododendron for further reseach that on classification of Rhododendron and germplasm resources of protection and utilization in caryologia to provide necessary and technical support. Now the result is reported on the following:1. In the production process Of the two Rhododendron, low concentration of Autumn narcissus alkali,8-hydroxyquinoline, a mixture of ice-water will destroy the microtubules, get more middle split cells. But it can cause chromosomal shorten distortion or even formed polyploid that used high levels of autumn narcissus element or treated in long time, the processing method of Autumn narcissus alkali is not only need a lot of exploration, but the price is also too high, the autumn, and the inappropriate use of Autumn narcissus alkali will cause neurotoxicity; If the processing time is undeserved, the method of using 8-hydroxyquinoline will also lead to chromosome highly concentrated,shorten, and it adverse to promote karyotype analysis. Compared with the former two pretreatment, ice-water mixture had no effect on the basic form of chromosome, and it is a simple and feasible method. Experiments have found that two of the Rhododendron root in 0-4℃low temperature conditions with ice-water treating 24hours can be got a lot of clear middle chromosome image used in karyotype analysis. So using ice-water mixture in 0-4℃and processing 24 hours is a safe, convenient and effective material pretreatment method, with 1 mol·L-1 HCl are obtained from 10 min,5 mol·L-1 HCl are obtained from the 4 min, the producer effect is better that Rhododendron decorum is used of improved phenol magenta dyeing 72 h,96 h, Rhododendron lanatum is used of improved phenol magenta dyeing 96 h. 2. In the plant of two Rhododendron, the Chromosome numbers of Rhododendron decorum and Rhododendron lanatum is 26.3. In the plant of two Rhododendron,The relative length of Rhododendron decorum is 1.67-5.62, and Rhododendron lanatum is 2.47-5.10.4. In different temperature, the sprouting days and germination rate of two Rhododendron is different. Rhododendron decorum in the variable temperature conditions is higher than constant temperature, the sprout germination days is shorter than constant temperature. In the variable temperature 15-20℃,20-25℃conditions, the germination rate of Rhododendron decorum were respectively for 81% and 83%,the sprouting days were 9 days and 8 days; In 20℃,25℃constant temperature conditions, the germinative rate of Rhododendron decorum were respectively 76% and 73%, the sprouting days were 10 days and 12 days, So the germination percentage of Rhododendron decorum which under 20℃constant temperature is higher than in 25℃constant temperature,and the sprouting days is shorter than in 25℃constant temperature. In this experiment, the sprouting days of Rhododendron decorum in 25℃were 12 days, this conclusion is different from the conclusion of Geng Yuying who reported that the sprouting days of Rhododendron decorum is 8 dyas in temperature 25℃. In the variable temperature 15-20℃,20-25℃conditions, the germination rate of Rhododendron lanatum were respectively for 82% and 77%,the sprouting days were 11 days and 14 days; In 20℃,25℃constant temperature conditions, the germinative rate of Rhododendron lanatum were respectively 81% and 73%, the sprouting days were 13 days and 15 days, So the germination percentage of Rhododendron lanatum which under 15-20℃variable temperature is highest and the sprouting days is shortest.5.In four different length, the best is that to draw materials from Rhododendron decorum and Rhododendron lanatum in 0.5-1.0mm, in 0.5mm or 2.0mm are disbennifit to observe the chromosome.This ultimateness is obviously different from other plants that need draw materials from roottip about 1cm.6. Because of the smaller chromosome of Rhododendron, this paper is only study the number of chromosome and karyotype analysis in two Rhododendron elementary. Nevertheless, the relationship between the two types of Rhododendron still need further research.