Study On Turf Quality And Heat Tolerance Of Native Creeping Bentgrass

The regional experiment was carried out in accordance with the randomized complete blocks design, it was adopted to comprehensively evaluate and compare the turf quality and heat tolerance of thirteen wild A.stolonifera L.and CK (Putter) in southwest of China in this article. The results showed that:1. In this experiment, All materials couldn't flower and fruit naturally in this area, but the burst stem planning method is quick turf-establishment After 3 days the materials were survive. After 5 days they grew the primary creeping stems and 15 days later appeared the secondary creeping stems; During the fastigiumof growth (4～5month), the average of growth rate the primary creeping stems was 0.84cm/d. The Populations of 05GA1, 05GA2, 05GA4, 05GA5 grew most quickly 0.89～0.92 cm/d, the lowest was 05GA6 (0.74 cm/d). The average of growth rate the secondary creeping stems was 0.53cm/d. The total tiller number among the tested populations varied from 3.50 tillers/stems to 7.00 tillers/stems. The average of tuff-establishment time was 43d, 05GA2, 05GA4, 05GA5 and CK were 38d, 38d, 39d, 40d, the other materials varied from 41d to 45d.2. There are significantly relative in grow characteristics, the average of growth rate the primary creeping stems and total tiller number (P＜0.01) (r=0.701, and 0.740, respectively), but not with the secondary creeping stems, above-ground biomass and delow-ground biomass. A total trend of resource allocation is stem＞root＞leaf.3. During high temperature (36℃/26℃), the stress time prolonging, the degree of scorching and numbers of plant death were increased. At the same time the change of leaf color was from green to yellow even fading and the change of leaf teture was from hard to soft. All materials showed light scorching at 3 days, but a few of creeping bentgrass 05GA6 and 05GA8 died., middle scorching at 5 days, serious scorching at 7 and 9 days, while the survival rate of most materials were 100%, 65～90%, 30～75%, 10～35% respectively. 4. In this experiment, all materials could be alive safely in summer. The oversummering rate of different material from 84.00% to 56.67%; the comprehensive evaluation of the survival rate, physiological index, by membership function method indicated that 05GA5 was the most resistant to heat tolerance and subordinative function value was 0.6855, 05GA8 was the weakest resistant to heat tolerance (0.2406), the residue materials were medium.5. The curves of diurnal variation in Pn of A. stolonifera L leaves had two peaks, but the time of midday and the second peaks among different material were significant. At10:00am or 12:00am, the first peaks of different material appeared, the time of midday of 05GA5 and CK appeared at13:00pm and the time of second peaks appeared at14:00pm; the time of midday of 05GA2, 05GA7 and 05GA13 appeared at15:00apm and the time of second peaks appeared at16:00pm or 17:00pm; the time of midday of the residue materials appeared at14:00pm and the time of second peaks appeared at15:00pm or 17:00pm. The value of first peaks, midday and second peaks were10.97～13.66umol.CO₂.m^-2.s^-1, 4.26～8.81umol.CO₂.m^-2.s^-1 and 7.47～10.24umol.CO₂.m^-2.s^-1 among different material.6. The characteristic parameter of light response curve of tested material were significant, the AQY was 0.031μmol m^-2.s^-1 to 0.070μmol m^-2.s^-1; the R_day was -4.276μmol m^-2.s^-1 to 0.145μmol m^-2.s^-1; the A_max and L_cp were 14.896μmol m^-2.s^-1 to 33.39μmol m^-2.s^-1 and 14.999μmol m^-2.s^-1 to 60.383μmol m^-2.s^-1. 05GA7 has the highest L_cp (60.383μmol m^-2.s^-1), and the L_cp of tested material from high to low as follows: 05GA7＞05GA5＞05GA12＞CK＞05GA8＞05GA1＞05GA10＞05GA9＞05GA6＞05GA4＞05GA13＞05GA11＞05GA3＞05GA2. The variation in rang of L_sp was 294.194μmol m^-2.s^-1-550.8681μmol m^-2.s^-1, 05GA5 has the highest L_sp. Most material's L_sp were lower than 500μmol m^-2.s^-1 excluding 05GA4, 05GA12 and 05GA13. 05GA5 andCK have lower Rd_ay. This implied that no difference in adaptation to light among different materials was observed.7. Taking 7 indices about texture, density, uniformity, color, green period, rust disease resistance and heat resistance to comprehensive evaluated on turf quality by nine point systematic evaluation method, the results indicated that: before summer, the average of scores of tested material was 7.7, 05GA5 (8.4), 05GA8(7.1), the residue materials were medium; during summer, the average of scores of tested material was 6.9, 05GA5 (7.8), 05GA8(6.2); afier summer, the average of scores of tested material was 7.4, 05GA5 (8.3), 05GA8(6.7), the residue materials were medium. The scores of 05GA5 (8.1) and 05GA2 (7.9) were better than CK (7.6) in whole year's field experiment.8. Taking 7 indices about texture, density, uniformity, color, maturate time, green period and heat resistance to comprehensive evaluated on turf characters by Grey relation analyses, which result is in accordance with the appraisal by nine point systematic evaluation method. The results indicated that: The maximum correlation degree was 05GA5 (0.6841) and was close to reference ones, the medium correlation degrees was 05GA8 (0.5831) and exist enormous difference to reference ones. The turf quality of other materials supplied proved to be not the best or not the worst.9. Combining field experiment with pot experiment: Because of comperatively short maturate time, high oversummering rate of 05GA5, it was higher correlation degrees and superior to CK, which was suitable to eatabolish turf in this region.