羊草稳定同位素值、叶绿素值与其营养品质分析

The analysis of stable isotope value,chlorophyll and nutritional quality of Leymus chinensis

测定3种土壤条件下不同品系羊草(Leymus chinensis)稳定同位素(δ13C)值、叶绿素(SPAD)值及主要营养成分,并探讨了其相关性与回归关系。结果表明,土壤因素对羊草BG-2、B品系的δ13C值和SPAD值有较大影响,对羊草Y1品系SPAD值影响不大;羊草δ13C值与土壤有机质、碱解氮、全盐及土壤水分含量相关系数在0.737~0.800,除与土壤全盐含量之间显著相关外(P<0.05),与其他的土壤因子均极显著相关(P<0.01)。羊草δ13C值在-28.613^-27.383,与粗蛋白、粗纤维、赖氨酸含量之间显著相关,相关系数分别为0.533、0.591、0.401;与其必需氨基酸、牧草能量之间显著相关,相关系数分别为0.469、0.649;羊草SPAD值37.075~42.893,与粗蛋白、中性洗涤纤维、磷、粗灰分和干物质含量的相关系数在0.596~0.783,均表现为显著或极显著相关。与脯氨酸含量相关系数最大,为0.902,与总氨基酸和必需氨基酸含量的相关系数在0.833~0.887,均表现为极显著相关。本研究表明,叶片SPAD值最能反映出羊草营养品质;羊草Y1、Y3品系的SPAD值、干物质、粗蛋白和能量含量较高,粗纤维含量较低,氨基酸总量以及必需氨基酸比例均占优势,是值得大力推广种植的羊草品系。

The stable isotope value（ δ13C）,chlorophyll（ SPAD） value and main nutrients of different varieties of Leymus chinensis which were planted in 3 different types of soils were determined and the correlation and regressions between these indices were explored and discussed. The results showed that the effects of the soil on δ13C and SPAD values of L. chinensis varieties BG-2 and B were high significant（ P〈0. 01）,while the effect on the SPAD value of the varieties Y1 were not significant. The correlations between the δ13C values of L. chinensis and the soil organic matter（ SOM）,available nitrogen（ AN）,total salt content（ TS） and water content（ WC） ranged from 0.737 to 0. 800（ P〈0. 01）. In addition to that the regression relationship of the δ13C value of L. chinensis with the total salt content of the soil was significant（ P〈0. 05）,its regression relationships with the other measured soil factors were all high significant（ P〈0. 01）. The correlations indices between the δ13C values（- 28. 613 ^- 27.383） and the crude protein（ CP）,crude fiber（ CF） and lysine were 0. 533,0. 591 and 0. 401 respectively and the regression relationships were significant. The correlations with the indispensable amino acid（ IAC） and energy content were 0. 469 and 0. 649,respectively and the regression relationships were significant. The correlations between the SPAD values of L. chinensis and the CP,neutral detergent fiber,phosphorus,crude ash and dry matter（ DM）content were relatively high with the correlation indices ranging from 0. 596 to 0. 783. The correlation between the SPAD values（ 37. 075 ~ 42. 893） and the proline was the highest（ R2= 0. 902,P〈0. 01）. The correlations between the SPAD values and the total amino acid（ TAA） content and IAC content ranged from 0. 833 to 0. 887 and the regression relationships were both high significant. These tested indices performed significant regression relationship. In conclusion,the SPAD value was the best index to suggest the nutrition quality of L. chinensis. The Y1 and Y3 varieties of L. chinensis should be widely cultivated as they had relatively high SPAD value,DM,CP,energy content,the proportion of TAA and IAC and relatively low CF content.