| The experiment was conducted in DaChaigou Township, Anding District of DingXi City, Huajialing Township of Tongwei County, Forage test site at Lanzhou of Gansu Agricultural University, from March to October in 2008. The effects of ecological regions on days to maturity, grain filling rate, seed yield, LAI at different periods, ratio of fresh to hay, fresh yield and quality of 7 oat cultivars(Baiyan No. 7, 409, 709, Denmark 444, 343, Qingyin No.2, Sweet oat) were studied. The result are as follows:.(1) In different ecological regions, The days to maturity of oats varied significantly. With the increasing altitude, temperature diseased, nutritive and reproductive growth of oats prolonged, which caused prolonging of the days to maturity, with the longest in Dachagou (averagely 125d) and shortest in Anding District (averagely 90d). The days to maturity in Huajialing were averagely 109d and GAU 98d.(2) In different ecological regions, the grain filling rate was significantly different. During the entire of grain-filling process, with the increasing altitude and decreasing temperature, the speed of grain filling reduced.The aiatitude of Anding and GAU are 1898.7m and 1517.3m, respectively, much lower than that of Huajialing (2242m) and Dachaigou(2594m). However, their grain filling speed was much faster. Among 7 varieties, Qingyin No.2, 343, 409 and 709 had significantly faster filling speed at GAU than in Dachaigou; Denmark 444, Baiyan No. 7 and sweet oat had faster grain filling in Anding District than in Dachaigou.(3) Oats had a "S" type plant height variation. From three leaf stage to heading stage, Changes in plant height were mild and increased quickly after the heading stage; then reduced gradually to the end at maturity. The effect of different ecological regions on plant height was significant. At high altitudes regions, with lower temperature and abundant precipitation, oat increased its height significantly; while at low-alatitude areas with higher temperatures and less rainfall, oat shortened its life history with lower plant height. From three leaf stage to maturity, oat height was the lowest in Anding District, with 73.74cm at maturity, which was only 52.1% of that in Dachaigou.(4) The effect of different ecological regions on LAI was significant different. From three leaf stage to plant maturity, with the growing environment changing from dry to wet, low to high altitude, LAI increased significantly from booting to heading stage and declined after, with the highest at GAU (5.3) and the lowerest at Anding District (1.024).(5) The ecological regions had significant effect on grass yield. At grain-filling stage, with the increasing elevation and rainfall and decreasing temperature, oat grass yield increased significantly. The same trned was observed at maturity. At grain-filling stage, fresh yield was the lowest at Anding(18776.40 kg/hm~2),Hajialing had the highest (62390.46 kg/hm~2), 69.90% more than the former. Within 7 varieties, sweet oat, 709 and 343 had the highest fresh yield which is suitable for grass collection.(6) The results of ratio between fresh and hay of 7 varieties at 4 different regions showed that it was a reversing "S" type, and varied significantly at different regions. In the high-alatitude regions, it increased as the prolonging life hiftory, and reduced under higher temperature and drought stress in low-alatitude regions. From three leaf to milk stage, it was the lowest at Anding and the highest at GAU (higher 41.32% than the former). No significant difference was observed in Huajialing and Dachaigou.(7) Seed yield also showed significantly difference at different regions. With the increase of elevation and temperature difference between day and night, the photosynthesis enhanced during daylight and respiration reduced at night, resulting in more organic matter accumulation and higher seed yield. The average grain yield was the highest in Hajialing (5618.52kg/hm~2), the lowest at Anding(1622.96kg/hm~2).(8) In different ecological regions, signigifant differences were observed on thousand grain weight, effective tillers and number of rings. With the increasing altitude and decreasing temperature, thousand grain weight and effective tillers increased. No significant difference was observed on number of rings. Number of spikelet and grains were the highest at Dachaigou and the lowest at Anding (35.13% and 32.48% of the former, respectively).(9) The effect of different ecological regions on oat hay nutrition was significant. The general trend indicated that from dry to wet climate, oat hay reduced its crude protein, increased ADF and CF. During the grain filling stage, crude protein was the highest at Anding and the lowest in Dachaigou (26.41% lower than the former); ADF was the highest in Hajialing and lowest at Anding area (36.41% lower ).(10) The crude fat andβ-glucan also showed significant difference. In the low rainfall and drought stress areas, oat accumulated moreβ-glucan; in mild climate areas with rich rainfall,β-glucan content was lower. Secondly, the relatively high temperature during maturity could induce higherβ-glucan content. The crude fat at Anding was 77.12% lower than that in DaChaigou;β-glucan was the highest in Anding, 32.99% higher than in Hajialing. In terms of cultivars, 409 and Baiyan No. 7 had higherβ-glucan than other cultivars.(11) During the whole life history, water and heat, elevation, sunlight and temperature in growing areas affected the process of oat growth from different aspects. Oat had higher hay and grain yield in the relatively high altitude areas than lower and drier areas. Therefore, Tianzhu County and Tongwei county are suitable for the production of oats. |
