Genetic diversity and geographic pattern of wild lotus （Nelumbo nucifera） in Heilongjiang Province

1MATERIALS AND METHODS1.1PLANT MATERIALS FROM AUGUST TO SEPTEMBER IN2004,WE TRAVELED EX-TENSIVELY IN HEILONGJIANG PROVINCE LOOKING FOR THE WILD LOTUS.THE WILD LOTUS WAS FOUND AT40LOCALITIES AND49ACCESSIONS OF SAMPLES WERE COLLECTED AT THESE LOCALITIES(FIG…

Genetic diversity and geographic pattern of wild lotus (Nelumbo nucifera) in Heilongjiang Province

Based on 47 accessions from Ussuri River Valley, Songhua River Valley and Heilong River Valley together with 2 accessions from Russia and 27 accessions of cultivated lotus from other provinces in China, genetic diversity of wild lotus (Nelumbo nucifera) were revealed using RAPD and ISSR markers. Twenty RAPD primers generated 113 loci, of which 71.68% were polymorphic across all sam-ples. The expected heterozygosity was 0.1583. The percentage of polymorphic loci and expected het-erozygosity in the wild lotus were 50.44% and 0.1241, respectively. The parameters of the cultivated lotus were slightly higher, 53.98% and 0.1651 corre-spondingly. Sixteen ISSR primers produced 90 loci. The percentages of polymorphic loci and expected heterozygosity were 41.11% and 0.0851 at species level, 28.89% and 0.0661 for the wild lotus, and 32.22% and 0.0963 for the cultivated lotus. AMOVA analysis of the wild lotus showed that a small number of variances exist among the 3 river valleys (21.68% for RAPD with Gst=0.1312 and 15.11% for ISSR with Gst=0.1352). The molecular variances of both the wild and the cultivated lotuses came predominantly from within the 3 river valleys and the cultivated samples (73.25% for RAPD and 81.11% for ISSR). Variance components from the wild and the cultivated lotus accounted for 19.17% for RAPD and 13.17% for ISSR, and variations among the valleys and the culta seemed the least important (7.585 for RAPD and 5.725 for ISSR). Neighbor-joining analysis demon-strated that considerable differentiation happened between the wild and the cultivated lotus. The wildlotus at middle reaches of the Songhua River Valley seemed to be the centre of remnants, from which it spread to the Ussuri River Valley and the Heilong River Valley. The very limited genetic diversity sug- gests that the wild lotus has experienced severe bot- tleneck effect, founder effect and rebirth effect. Con- sidering its long evolutionary history, scarcity of ge- netic variations and importance in wetland ecosys- tems, we appeal to take lawful measures to protect the wild lotus. For conservation purpose, special at- tention should be paid to the lotus at the middle reaches of the Songhua River Valley.