青藏高原青稞蛋白质含量空间分异规律及其与环境因子的关系

【目的】揭示不同环境因子对青藏高原青稞籽粒蛋白质含量(GPC)的影响程度,完善青稞GPC空间分异与环境因子的关系,明确青藏高原不同地区青稞GPC的环境响应。【方法】利用农学和地理学相结合的研究方法,研究青藏高原青稞GPC的分布特征及其与环境因子之间的关系。【结果】在地理水平方向上,青藏高原青稞GPC总体呈现出斑块状交错分布的格局和南高北低的态势,并形成了2个青稞GPC高值区。其中一个是介于东经100.0°—102.5°、北纬35.0°—37.5°,以青海共和、贵德、门源、同德和甘肃合作为中心的青藏高原东北部高值区,这一区域青稞GPC平均值为(13.1163±0.5939)%;另一个是介于东经86.0°—92.0°、北纬28.0°—29.0°,以西藏贡嘎、拉孜、尼木、扎囊、聂拉木、堆龙德庆、桑日、康马为中心的青藏高原中南部高值区,这一区域青稞GPC平均值为(12.8715±0.6609)%;在地理垂直方向上,随着海拔升高,青稞GPC呈现出"倒N"型分布格局,即从海拔3 000 m以下的高值区(此海拔区间青稞GPC平均为(10.8650±1.8600%))随着海拔的升高,青稞GPC逐渐减少,在海拔3 000—3 300 m达到低值区。在海拔3 000—3 300 m,随着海拔的升高,青稞GPC逐渐增加,在3 600—3 900 m达到最高值区,此海拔区间青稞GPC平均为(10.8937±2.0719)%。此后,又随着海拔的升高,青稞GPC逐渐减少。影响青稞GPC的环境因子从大到小的顺序是土壤速效氮含量抽穗-成熟期日照时数出苗-分蘖期平均气温日较差分蘖-拔节期平均气温日较差拔节-抽穗期相对湿度。【结论】影响青稞GPC最大的环境因子主要是土壤因子,其次是气候因素,地理因子无明显影响。影响青稞GPC的土壤因子主要是土壤速效氮含量,气候因子主要是抽穗-成熟期日照时数、出苗-分蘖期平均气温日较差、分蘖-拔节期平均气温日较差和拔节-抽穗期相对湿度。青稞GPC含量随着分蘖-拔节期平均气温日较差、拔节-抽穗期相对湿度的增加而显著增加,但随着抽穗-成熟期日照时数、出苗-分蘖期平均气温日较差和土壤速效氮含量的增加而显著降低。

Spatial Distribution Regulation of Protein Content of Naked Barley Varieties and Its Relationships with Environmental Factors in Qinghai-Tibet Plateau

【Objective】 The objective of this study is to reveal the effect of different environmental factors on grain protein content (GPC) of naked barley, to understand the relationship between naked barley GPC distribution characteristics and environmental factors, and to get clear on GPC acclimation of naked barley varieties from different areas to the environment of the Qinghai-Tibet plateau. 【Method】 Based on the method of agronomy combined with geography, naked barley GPC distribution characteristics in Qinghai-Tibet plateau was studied. 【Result】 Along the horizontal direction in Qinghai-Tibet plateau, GPC spatial distribution characteristics of naked barley varieties appeared in a macrocosm trend of high-in-south and low-in-north with a staggered pattern, and there developed two regions of higher GPC. One of the regions of higher GPC exists between the area with longitudes from 100.0°E to 102.5°E and with latitudes from 35.0°N to 37.5°N. And the average GPC of barley varieties in this region is (13.1163±0.5939)% in north-eastern Qinghai-Tibet plateau with distribution centers including Gonghe County, Guide County, Menyuan County and Tongde County in Qinghai Province, and Hezuo County in Gansu Province. Another region of higher GPC existed between the area with longitudes from 86.0°E to 92.0°E and with latitudes from 28.0°N to 29.0°N. And the average GPC of barley varieties in this region is (12.8715±0.6609)% in south-central Qinghai-Tibet plateau with distribution centers including Gongga County, Lazi County, Nimu County, Zhanang County, Nielamu County, Duilongdeiqing County, Sangri County and Kangma County in Tibet. Along the vertical direction with altitudes, GPC distribution pattern appeared in shape of inverted letter N. The average GPC value is (10.8650±1.8600)% at the altitudes below 3 000 m. GPC gradually decreased with altitude increasing, and then reached to the lower value at the altitudes from 3 000 m to 3 300 m. And GPC gradually increased with altitude increasing at the altitudes above from 3 000 m to 3 300 m, and then reached to the highest value at the altitudes from 3 600 m to 3 900 m with average GPC value of (10.8937±2.0719)%. Hereafter, GPC of barley varieties decreased gradually with altitude increasing. The magnitude of effect of environmental factors on naked barley GPC follows an order of soil available N content > sunshine hours during the growth period from heading to maturation > average diurnal temperature range during the growth period from seedling from tiller > average diurnal temperature range during the growth period from tiller to elongation > relative humidity during the growth period from elongation to heading. 【Conclusion】 Soil factors are the main environmental factors with the greatest impact on GPC, and followed by climatic factors, the effect of geographical factors on GPC is not apparent. Soil available N content is the main soil factor influencing barley GPC, and sunshine hours during the growth period from heading to maturation, average diurnal temperature range during the growth period from seedling from tiller, average diurnal temperature range during the growth period from tiller to elongation and relative humidity during the growth period from elongation to heading are the main climatic factors. Barley GPC increased with the increase of average diurnal temperature range during the growth period from tiller to elongation and relative humidity during the growth period from elongation to heading, though decreased significantly with the increase of sunshine hours during the growth period from heading to maturation and average diurnal temperature range during the growth period from seedling to tiller and soil available N content.