Distribution Characteristics,Flowering and Seeding of Dendrocalamus sinicus in Yunnan,China

Dendrocalamus sinicus Chia et J.L.Sun is one of the endemic and the most important economic bamboo species in Yunnan Province,China.In order to protect and excavate the native germplasm resources of this species,18 typical populations were investigated and the flowering and seeding of D.sinicus in Yunnan Province in the past years were analyzed.The results show that D.sinicus is narrowly distributed in Southwest Yunnan,with the distribution centre locates in the lower and medium mountain areas at the altitude of 1 0001 500 m above sea level in Cangyuan,Ximeng and Menglian Counties,ranging in 22° 09′23° 30′N,98° 56′99° 37′E.Meanwhile,from south to north within distributions,the culm type of D.sinicus shows an obvious trend as from bending-culmed,mixed type,to straight-culmed.The average diameter at the breast height is significantly and positively correlated with the altitude of populations.Sporadic flowering of D.sinicus was observed in the wild,especially for the straight-culmed type,while the seed setting was rare,and the seed setting rates were as low as from 0.34% to 0.64%,which may be mainly due to sporadic flowering of individual culms or clumps and protogynous flowers.Apis cerana Fabricius may be one of the important pollinators of D.sinicus.