Study On The Space-time Pattern Of Reproductive Ecological Characters Of Apocynum Venetum Population In The Songnen Plain

Apocynum venetum is a kind of plant which can grow well in the salina and sand, and is resistant to alkali, salina, droughty. It is not only important to environment, but also important to economy. The research about the reproductive ecology of Apocynum venetum has not been reported. For this reason, our work studied the space-time pattern of reproductive ecology of Apocynum venetum of Songnen Plain. The results showed that:(1) The indexes of reproductive characteristics Apocynum venetum populations are different at different flowering periods.The variance analysis showed that the variation coefficient (CV) of every index of reproductive characteristics at four flowering periods are: fruit setting percentage coefficient: 77.5%; reproduction allocation: 76.94%; fruit number: 72.33%; floret number: 50%; fruit weight: 24.49%; seed number per fruit: 23.28%; 1000-seeds weight: 8.83%. All reached significant level (P<0.05). Through generalizing, the ecology plasticity of reproductive characteristics of four flowering stage Apocynum venetum populations are all very big, can be compartmentalized three grades: fruit setting percentage, fruit number, reproductive allocation > floret number >seed number per fruit, fruit weight, weight of 1000-seeds.(2) The indexes of reproductive characteristics of Apocynum venetum populations all presented unvarying dynamic regular pattern at the four periods. Biomass, floret number of Apocynum venetum populations that flowered in June 12th are the most; Biomass is 12.34 g, floret number is 456.4; Biomass, floret number of Apocynum venetum population that flowered in July 3th are the least. Weight of 1000-seeds flowered in June 19th is the most, and it is 0.6081g; weight of 1000-seeds flowered in July 3th is the least. Fruit number and weight flowered in June 26th are the most, they are 3.24 g, 0.2894 g; fruit number and weight flowered in June 12th are the least. Fruit setting percentage flowered in July 3th is the most, and it is 1.40%; fruit setting percentage flowering in June 12th is the least.(3) The reproductive characteristics of Apocynum venetum are different not only in the period of flowering, but also in different parts (stem and branch). The variance analysis showed that the difference of the content of reproductive characters of Apocynum venetum population between stem and branch reached the significant level (P<0.05), The contribution of stem to reproductive is great than branch. The difference from big to small is: reproductive allocation>fruit number> weight of per fruit>weight of 1000-seeds>seed number per fruit.