快速准确无损测定牧草种子活力是当前种子生理研究中的一项重要内容，试验以甜燕麦种子为材料，采用近红外光谱结合主成分-马氏距离模式识别方法鉴别了3种不同活力的燕麦种子，研究结果表明，在4000—6900cm^-1波数范围内的光谱，通过SNV（Standard Normal Variate）预处理方法，用4个主成分建立的模型效果最佳，模型对校正集样本和预测集样本的鉴别率都分别达到100％，该研究利用近红外光谱技术为快速准确无损测定种子活力提供了一条新途径。
Elytrigia Desv. is widely distributed throughout the world and is represented with species of various levels of ploidy including diploids, tetraploids, hexaploids, octaploids, and decaploids. The distribution pattern of these ploidy levels, however, is not well-defined. In this study, the levels of ploidy for 64 accessions of Elytrigia from 25 countries were determined with microscopic procedures. The results showed that accessions of E. intermedia and E. repens were grouped into three distinct levels of ploidy including diploids, tetraploids and hexaploids. For E. elongata, E. pontica, and E. caespitosa, it was found that two ploidy levels presented, and only one ploidy level was in those of E. hybrid, E. pycnantha, E. pungens, E. juncea, and E. alatavica. Karyotype analysis indicated that the karyotype formula of diploid, tetraploid and hexaploid of E. intermedia was 2n = 2x = 14 = 6m + 6sm + 2st, 2n = 4x = 28 = 2M + 10m + 16sm and 2n = 6x = 42 = 4M + 18m + 20sm, respectively. Furthermore, the karyotype formula of three germplasms in tetraploid of E. intermedia was 2n = 4x = 28 = 2M + 10m + 16sm, 2n = 4x = 28 = 4M + 22m (sat) + 2sm and 2n = 4x = 28 = 4M + 12m + 12sm (sat), which were not completely uniform. Therefore, it could be suggested that the studies about chromosome constitution would be helpful for the detail understanding of the diversity of germplasm resource in Elytrigia and promoting the utilization in the crop molecular breeding.
MAO Pei-shengHUANG YingWANG Xin-guoMENG LinMAO Pei-cbunZHANG Guo-fang
