不同冬小麦品种在3种质地土壤中氮代谢特征及利用效率分析

为明确不同土壤质地条件下不同品种冬小麦(Triticum aestivum)的氮代谢和利用特征,筛选与土壤质地相适宜的高产和氮高效利用的优质小麦品种,采用大田试验的方法,在同一生态类型区砂土、壤土和黏土3种质地土壤上,以当地生产上大面积应用的强筋小麦‘郑麦366’(‘ZM366’)和中筋小麦‘矮抗58’(‘AK58’)、‘周麦22’(‘ZM22’)为材料,系统地研究了土壤质地对不同冬小麦品种主要生育时期叶片氨同化关键酶谷氨酰胺合成酶(GS)活性、游离氨基酸含量、花前和花后不同器官氮素积累和分配、氮素再分配等氮代谢过程及产量、品质和氮素利用效率等的影响.结果表明:在这3种土壤质地上,不同品种冬小麦旗叶GS活性和游离氨基酸含量均呈倒“V”型变化特征.各品种小麦旗叶GS活性、游离氨基酸含量大小及达到最大值的时期不一样,砂土条件下峰值早于壤土10天左右出现,且在5月22日已检测不到GS活性和游离氨基酸含量.花前和花后小麦地上部及各器官氮积累量(NA)、氮再分配量(NR)、成熟期籽粒产量和氮素当季利用率(NUE)均以壤土上为最高.氮素转运率(NRE)、花前再分配氮素对籽粒氮素的贡献率(NRC)、氮素生理效率(NPE)、氮收获指数(NHI)以砂土上为最高.其中,砂土上NRC达82.46％-95.84％,是花后的7倍左右;壤土和黏土条件下花后吸收的氮素在籽粒氮素的积累中占有较大的比例,贡献率分别为36.6％和29.2％.同一土壤质地上3个品种比较,在砂土上,GS活性、游离氨基酸含量、籽粒产量、蛋白质含量及NUE和NPE以‘郑麦366’最高,而壤土上以‘矮抗58’最高,黏土上则以‘周麦22’最高.因此,在生产上应培育和选择与土壤质地相适应的小麦品种,砂土地种植‘郑麦366’,壤土条件下种植‘矮抗58’,黏土条件下种植‘周麦22’,可以在获得较高产量和品质的同时,提高氮素利用效率.

Research on nitrogen metabolism characteristics and use efficiency in different winter wheat cultivars grown on three soil textures

Aims The objective was to clarify the relationship between soil texture and characteristics of winter wheat cultivars in regard to nitrogen metabolism and utilization with different protein content. We planted the cultivars on three types of soil with different texture and looked for the optimum winter wheat cultivar under specific soil texture conditions.
Methods Field experiments using three winter wheat cultivars (‘ZM366’, ‘AK58’ and ‘ZM22’) with different protein content were carried out on soils of three textures, i.e. sandy, loam and clay soils, at the city of Huaxian, Henan Province, China during the 2011-2012 winter wheat growing season.
Important findings Soil texture greatly affected patterns of N metabolism and utilization efficiency. Glutamine synthetase (GS) activity and free amino acid content in the three varieties graphed as inverted “V”-shapes with different peak time depending on the soil texture. The peak of plants grown on sandy soil occurred 10 days earlier than plants on loam and clay soils. Moreover, on May 22 the GS activity and free amino acid content of plants grown on sandy soil was not detected. Cultivars grown on loam soil had the highest pre- and post-anthesis N accumulation (NA) of total plant, leaves, stems and grains, as well as nitrogen remobilization to grain (NR), grain yield and N use efficiency (NUE). Whereas, the highest N remobilization efficiency (NRE), contribution of N remobilized to grain nitrogen (NRC), N harvest index (NHI) and N physiological efficiency (NPE) appeared in the plants grown on sandy soil. Also, the NRC was 82.46%-95.84% and NR was about seven-fold higher than post-anthesis NA for plants on sandy soil. However, contribution of post-anthesis NA was higher for plants grown on loam soil and clay soil which were 36.6% and 29.2%, respectively. Among the three winter wheat cultivars planted on the same soil texture, ‘ZM366’ was the highest with GS activity, free amino acid content, grain yield, protein content, NUE and NPE on sandy soil. However, for loam soil, ‘AK58’ is the best, and ‘ZM22’ was the best on clay soil. Consequently, it is important to breed and cultivate winter wheat cultivars according to soil texture. We concluded that ‘ZM366’ is the most suitable cultivar for sandy soil, ‘AK58’ is the best for loam soil, and ‘ZM22’ is the best for clay soil, so as to obtain higher yield and high quality in winter wheat and improve NUE.