金沙江中游地区红山茶组植物的Giemsa C－带研究

研究了金沙江中游地区红山茶组植物的ＧｉｅｍｓａＣ－带。该地区的红山茶植物以四倍体为主，个别居群为二倍体或六倍体。居群间的Ｃ－带差异明显，Ｃ－带多出现在染色体端部。在四倍体和六倍体的Ｃ－带带型中，只能找到２条显相同Ｃ－带的同源染色体，通过与其它地区的红山茶植物进行比较，发现红山茶组植物的倍性从华东，华南经贵州，四川向云南逐渐增高，显Ｃ－带的染色体与染色体总数之比随信性增加而减少。文中指出华东或华南可能是红山茶组植物的起源地，而金沙江中游地区是其现代分化中心，这一地区红山茶的多倍体类群可能是异源起源的。

STUDIES ON THE GIEMSA C-BANDS OF CAMELLIA SPECIES,SECTION CAMELLIA FROM THE MIDDLE REACH OF JINSHAJIANG VALLEY

Section Camellia, belonged to the genus Camellia, is distributed in Japan, eastern and soutern parts of China. The results represented here showed that almost all the species of Section Camellia in eastern and southern China are diploids, and most of them in the Jinshajiang valley are tetraploids, while those in most parts of Yunnan Province are hexaploids. By using BSG C-banding method, the C-bands among populations studied here were different from each other, which was in accordance with their morphological variation of these populations. For each population, the C-bands showed in the distal region of the chromosomes, and only two of them were detected to be homologous in all chromosomes showing C-bands of tetraploids and hexaploids,however, the number of chromosomes showing C-bandings decrease as the ploidy increase. Compared the results represented here with the data previously reported by other authors, it was found that the ploidy of the species in section Camellia gradually increased from southern China and eastern China, via Guizhou, to Sichuan and Yunnan Province. So it was pointed out as follows: Section Camellia was originated in the eastern and southern China; Jinshajiang valley was the center of the modern differentiation of section Camellia. Both the tetraploid and hexaploid species in section Camellia was heterologous.