Technique Of Artificial Hybridization And Superior Family Selection Of Dendrobium Officinale In The Seeding Stage

The Dendrobium officinale is the leader of the top nine medicinal herbs in our country, D. officinale is the national second level protective plant and one of the scarcest medicinal herbs. Nowadays, the technology of cultivation has already been studied clearly. However, the chaotic germplasms and degenerations of varieties have become the bottleneck of the industrial development. Measurements of pollen vigor, hybridizations within species, agronomic characteristics, polysaccharide and alkaloid contents of each F1 generation have been carried out and compared among the crossbred combinations. The major results were as follows:1.The pollen of D. officinale was always in vigor throughout the flowering phase. The pollen vigor was only 29.4% in the buds, 70.6% in the bloom day, and decreased to 31.9% a week later. It remained still 21.2% twenty days after storing under the condition of dry and 4℃. The fructification rate was about 82.6% and 7.3%, respectively, when the cross and self pollination performed by hand from bloom day to fade day. At the same time, both the subsidiary pollination by insects outdoors and open pollination in the greenhouse could not breed the fruits. The major cause for this phenomenon was the characteristic structures of flower.2.The agronomic characteristics, polysaccharide and alkaloid contents have been distinctly diverse among F1 generation families of the crossbred combinations. Variation of families among Full-sibs was distinctly larger than Half-sibs, and the variation of families within Full-sibs was distinctly was smaller than Half-sibs. More concerns should be aroused on selecting and controlling parents in order to utilize heterosis of D. officinale effectively. Selecting and utilizing among F1 generation of Full-sibs could produce more genetic gain and consistency than Half-sibs. Six Full-sibs families (66×65,69×91,91×69,66×17,66×9,17×66) have been selected in the twenty-six participative families, they have showed some superior characteristics such as strong sprouting ability, superior morphological characteristics and high polysaccharide contents.