青藏高原裸大麦β-葡聚糖含量空间分异规律及其影响因子研究

Tibetan Plateau is one of the centers of origin for cultivated barley and important growing area for hulless barley in China. Hulless barley is rich in β-glucan with health benefits and it is an important staple food crops and pillar crops for economic development in local areas. β-glucan plays an important role in nurturing the hulless barley industry and promoting local economic growth. The relations between the β-glucan content of hulless barley in Tibetan Plateau and environmental factors were rarely reported. To this end, this project is intended to focus on the spatial differentiation and the effects of environment factors (climate and soil) on the accumulation of β-glucan, using the Tibetan Plateau as the carrier which has diverse ecological types and combining multip-point field sampling and comparative study from various elevations. In order to : (1) reveal the spatial differentiation rules of β-glucan content among various geographical levels and different altitudes; (2) determine the effects of environmental factors on the accumulation of β-glucan; (3) clarify the major environmental factors and regulatory mechanism that driving the spatial differentiation of β-glucan content of hulless barley in Tibetan Plateau. The findings will improve our understanding of the spatial differentiation of β-glucan content and its relations with environmental factors, and provide scientific basis for establishing production base of specialty barley and formulating reasonable cultivation techniques in Tibetan Plateau.

青藏高原是世界栽培大麦起源中心之一和我国重要的裸大麦(青稞)种植区。裸大麦是当地重要粮食作物和经济发展支柱作物，富含保健功效的β-葡聚糖。β-葡聚在培育裸大麦综合产业、进而促进当地经济发展中具有重要作用，但是对青藏高原裸大麦β-葡聚糖含量与环境因子关系的研究鲜见报道。为此，本项目拟以生态类型多样的青藏高原为载体，通过多点大田采样和不同海拔梯度对比试验，重点研究裸大麦β-葡聚糖含量空间分异规律及环境(气候、土壤)因子与栽培因子对β-葡聚糖含量积累的影响，旨在：1)揭示青藏高原裸大麦在不同地理水平和不同海拔梯度上β-葡聚糖含量的空间分异规律；2)明确不同环境因子和栽培因子对β-葡聚糖含量积累的影响程度；3)阐明驱动青藏高原裸大麦β-葡聚糖含量空间分异的主导环境因子与调控机制。研究结果将从理论上完善大麦β-葡聚糖含量空间分异规律及其与环境因子和栽培因子的关系，并为青藏高原建立特用大麦生产基地和制订合理栽培技术提供科学依据。

采用83个样点数据，研究了青藏高原栽培大麦β-葡聚糖含量的分布特征。结果表明：在地理水平方向上，青藏高原栽培大麦β-葡聚糖含量总体呈现出斑块状交错分布的格局，并形成了以青海贵德、同德，甘肃夏河、合作为中心的青藏高原东北部和以西藏江孜、白朗、谢通门、日喀则、拉孜、康马、贡嘎、曲水为中心的青藏高原西南部等两个栽培大麦β-葡聚糖含量高值区；在地理垂直方向上，栽培大麦β-葡聚糖含量呈现出双峰曲线分布格局，在海拔2700.0m~3000.0 m和3600.0m~3900.0 m之间分别形成2个高峰区，这2个高峰区栽培大麦β-葡聚糖含量的平均值分别为5.7%±1.7%和4.6%±1.1%；对栽培大麦β-葡聚糖含量影响重要值指数在40.0%以上的因子依次是籽粒颜色﹥穗密度﹥ 9月平均相对湿度﹥ 土壤速效氮含量﹥土壤速效钾含量﹥6月平均气温日较差﹥≥10 ℃积温﹥年均气温﹥ 土壤速效磷含量﹥9月平均气温日较差。