Study On Ecological Adaptability Of Poa.Pratensis.L Populations In Subtropical Humid Area

This experiment had performed with analysis on thirteen wild Poa pratensis and two varieties (Midnight and Baron) were selected as check. The growth, resistance characteristics and turf characters were studied from 2005 to 2007. And evaluate the tested varieties of Poa pratensis ecological adaptability by set pair analysis. The results showed that:1. There are significant difference in grow characteristics and maturate time .In the maturation, the growth rate were significantly (P＜0.01) among the tested populations of Poa pratensis .Populations of the highest was 05P 13 (3.98mm/d); the lowest was 05P06 (0.12mm/d).The total tiller number among the tested populations of Poa pratensis varied from 38.0 tillers/plant to 161.33 tillers/plant. The rhizome characteristics were divided into 3 groups by cluster analysis method based on rhizome number, rhizome length and rhizome diameter parameters. The maximum capacity group included populations 05P01,05P06,05P08,05P10,05P13,05P15,05P16,Their total number of rhizome were 44.33, rhizome length were 6.7cm and rhizome diameter were 1.14mm;the medium capacity included populations 05P03, 05P04, 05P05, 05P07, 05P14, CK1, CK2, Their total number of rhizome were 41.67, rhizome length were 5.53cm and rhizome diameter were 0.72mm;the minimum capacity only included population 05P02, It total number of rhizome ,rhizome length, rhizome diameter directly were 15.33,3.27cm and 0.38mm. The maturate time were 58-81days in different populations. And the maturate time was high significant negative correlation to the branching angle which represents plant growing type (P＜0.01), R=-0.811.2. In this experiment, taking the classified evaluation method to comprehensive evaluated on heat tolerance, the results indicated that: 05P16, 05P04 and CK were the most resistant to heat tolerance, and their value of comprehensive evaluated on heat tolerance were forty-there, forty-two and forty; while 05P08 and 05P05 were weakest resistant to heat tolerance, and their value of comprehensive evaluated on heat tolerance were twenty-two and nineteen. The heat resistant abilities of the tested populations of Poa pratensis as following: 05P16＞05P04＞CK＞05P13＞05P10＞05P03＞05P01＞05P02＞05P15＞05P14＞05P07＞05P06＞05P05＞05P08.3. In this experiment, there exist enormous difference in different material, the variation in rang of leaves rate of rust disease, serious degrees of disease, comprehensive index were respectively 29% - 97%, 1.61-53.00, 2.60-3.90,the CV is 37.48%, 73.51% and 24.51% respectively. According to leaves rate of rust disease, serious degrees of disease, comprehensive index, tested material will be divided into three types: HS (Highly susceptible), MS (Medium susceptible), MR (Medium resistance). And 66% materials were susceptible type, only 33% were Medium resistance.4. The characteristic parameter of light response curve of tested material were significant, the psi was 0.02μmol m^-2.s^-1 to 0.08μmol m^-2.s^-1; the Rday was -2.33μmol m^-2. s^-1 to 0.8909μmol m^-2.s^-1; the P_max and L_cp were 1.4μmol m^-2.s^-1 to 32.2μmol m^-2.s^-1 and 10.543μmol m^-2.s^-1 to 106.25μmol m^-2.s^-1. 05P14 has the highest L_cp (106.2405μmol m^-2.s^-1), and the Lcp of tested material from high to low as follows: 05P14＞05P05＞05P08＞05P07＞05P16＞05P13＞05P06＞05P02＞05P15＞05P10＞CK＞05P01＞05P04＞05P03. The variation in rang of L_sp was 354.0483μmol m^-2.s^-1.1565.6231μmol m^-2.s^-1, 05P05 has the highest L_sp. Most material's Lsp were larger than 500μmol m^-2.s^-1 excluding 05P06, 05P07, 05P16. 05P01, 05P10 and CK1 have lower L_cp and Rd_ay.5. 10 indices were selected on growth characteristics and resistance characteristics to evaluate P.pratensis ecoadaptation by set pair analysis. The results showed that some tested material adapted well, including 05P04,05P13,05P14,05P15 and CK1 (r_k=0.61-0.70) ; 05P02 adapted weakly (r_k=0.43-0.47), other tested P.pratensis adapted in middle (r_k=0.50-0.59).6. Taking 8 indices about texture,density,uniformity, color ,maturate time, green period, rust disease resistance and heat resistance to comprehensive evaluated on turf characters, the results indicated that: The maximum comprehensive evaluated on turf characters group included populations CK1 (4.25)and 05P04(4.25); the medium included populations 05P01(3.75),05P10(3.75),05P13(3.63), 05P14(3.63), 05P15 (3.63); The minimum included populations 05P02 (2.75) and 05P07 (3.13) which because of weakly rust disease resistance and heat resistance.