诱变结合小孢子培养的氮高效大麦DH株系评价

为了筛选大麦氮高效种质资源,以花30和8份不同诱变来源的DH株系为研究对象,采用田间试验方法,设置高氮(160 kg·hm~(-2))和低氮(45 kg·hm~(-2))两个氮肥水平,研究不同DH株系对两个氮肥水平的响应,同时对不同氮效率类型DH株系的干物质和氮素积累、转运以及氮素吸收利用特性进行分析。结果表明,在两个氮肥水平下,根据平均产量可将花30和8份突变体材料划分为双高效型、低氮高效型、高氮高效型和双低效型四种类型。双高效型株系在两个氮肥水平下均具有较高的干物质和氮素积累量,而低氮高效型株系在低氮条件下具有较高的干物质和氮素积累量,这为籽粒产量的提高奠定了生理基础,也可以作为氮高效种质材料筛选的基础指标。本研究还分别获得了氮素吸收效率和氮素利用效率提高的DH株系,其中双高效型株系A9-47和低氮高效型株系A5-24在两个氮肥水平下氮效率的提高主要是由氮素吸收效率提高所致,双高效型株系A1-184在高氮水平下氮效率的提高主要是由于氮素利用效率提高所致,而低氮高效型株系A4-17在低氮水平下氮素利用效率也略高于亲本花30。这些种质材料的获得为氮高效育种及相关分子机理研究奠定了基础。

Evaluation of the Double Haploid Lines of Barley with High Nitrogen Use Efficiency Derived from Mutagenesis Combined with Microspore Culture

In order to screening the high nitrogen use efficiency(NUE) germplasm in barley, eight DH(double haploid) lines derived from different mutagenic source and their wild type Hua 30 were identified at filed conditions with high(160 kg·hm^-2) and low(45 kg·hm^-2) nitrogen inputs. The responses of DH lines to two nitrogen levels were studied. The characteristics of dry matter and nitrogen accumulation, transportation, nitrogen uptake and utilization were analyzed in DH lines with high NUE. The results showed that these DH lines were categorized into four types according to the mean yield under two nitrogen levels, including efficient-efficient(EE, yield higher than the mean yield of all the lines under both conditions), efficient-inefficient(EI, yield higher than the mean yield of all the lines only under low nitrogen condition), inefficient-efficient(IE, yield higher than the mean yield of all the lines only under high nitrogen condition), and inefficient-inefficient(II, yield lower than the mean yield of all the lines under both conditions). The EE lines had higher dry matter and nitrogen accumulation under both nitrogen levels, while the EI lines had higher dry matter and nitrogen accumulation under the low nitrogen condition, which laid a physiological foundation for the improvement of grain yield and also can be used as the basic index for screening high NUE germplasm materials. Meanwhile, the lines with the high nitrogen uptake efficiency and the high nitrogen utilization efficiency were obtained,respectively. The improvement of high NUE in the EE line A9-47 and the EI line A5-24 were mainly caused by the enhancement of nitrogen uptake efficiency. The improvement of high NUE of the EE line A1-184 under high nitrogen condition were mainly caused by the enhancement of nitrogen utilization efficiency. The EI line A4-17 also showed a little higher nitrogen utilization efficiency under low nitrogen condition than that of Hua 30. The germplasm materials laid the foundation for the high NUE breeding and the related molecular mechanism research.