摘要
本研究通过对目前正在推广应用的22个紫花苜蓿(Medicago sativa L.)品种生长、产量、品质、生理等相关指标的测定研究，以产量及品质为核心，进行了综合评价，旨在为生产实践提供高产优质的苜蓿应用品种，使种植者避免选用品种的盲目性，为关中及同类地区农业生产、畜牧业的发展及草业研究提供了初步的科学依据。也为苜蓿育种工作者提供了评价品种的第一手材料。
试验结果如下：
1．22个苜蓿品种的生长特性存在显著差异。大部分国外品种比本地品种关中苜蓿生长速度快，株高也高于本地品种，以德福、全能、Haygrazer植株最高，其生长速度也较快，达1.5～1.8cm/d以上，其再生性也好。本地品种关中苜蓿生长速度、高度及再生性能较差，休眠早，第一年仅能收二茬，国外品种第一年都可刈割三茬。
2．22个苜蓿品种产量差异显著，各茬次间草产量差异显著。国外品种维多利亚、苜蓿54鲜草产量最高，达60000kg/hm~2以上，而本地品种关中苜蓿鲜草产量仅为30800kg/hm~2，仅为维多利亚与苜蓿54的一半。干草产量以维多利亚与WL324最高，达15000kg/hm~2，是关中苜蓿(7333kg/hm~2)的二倍。无论鲜草产量还是干草产量，国外品种都比本地关中苜蓿要高。
3．22个苜蓿品种间品质差异显著，全年干草、每茬干草的粗蛋白、粗纤维含量差异显著。粗蛋白、粗纤维含量均符合国际一级标准，品质较好。其中以德福、WL323HQ最好，含粗蛋白23％以上。关中苜蓿的蛋白质含量20.75％，粗纤维16％。
4．22个苜蓿品种间蒸腾速率、气孔导度差异不显著，但其光合速率、细胞间隙CO_2浓度瞬时水分利用效率(WUE)及冠层温度之间均有显著差异。瞬时水分利用率以维多利亚、WL323ML、WL252HQ最高，达3μmol/mol以上，关中苜蓿水分利用效率接近3μmol/mol。Haygrazer、赛特冠层温度高，易衰老，皇后、牧歌抗热性好，草层代谢旺盛，不易衰老。
5．综合评价22个苜蓿品种，以维多利亚、全能、WL252HQ、苜蓿54较好，得分在37.5以上(总分50分)，而关中苜蓿得分为28.5，不到30分。综合利用时应选择综合得分较高的品种，如追求单一生产目的或做育种原材料应用其某些性状时，可在选择时，不考虑综合得分，只取其某些指标得分较高的品种。
This paper studied 22 alfalfa (Medicago sativa L.) cultivars which is applying in large area in production, related index of growing characters, yield, quality were measured, yield, quality were focused on to evaluated them synthetically. This research conducted in order to supply high yield, good quality, applicable alfalfa cultivars, to avoid blindness in cultivar choice, to give the element science basis for agriculture production, husbandry developing and prataculture research in Guanzhong and similar area. At the same time this research give a first-hand material of alfalfa cultivar evaluation for breeding researchers.
The results as follows:
1. 22 alfalfa cultivars had significant difference on growing characters. Most foreign alfalfa cultivars grew fast and were taller than native cultivar Guanzhong alfalfa. Defy, Total, Haygrazer were the tallest of all, and had growing rate more than 1.5-1.8 cm/d, and regrew quickly. Native cultivar Guanzhong alfalfa had lower growing rate, lower height, lower regrowing quality, and lower fall dormancy. In the first year, Guanzhong alfalfa got only 2 cuttings, and foreign alfalfa cultivars can got 3 cuttings.
2. 22 alfalfa cultivars had significant difference on total yield and different harvest yield. Victoria, Alfalfa 54 had more green grass yield that was more than 60000kg/hm2. Guanzhong alfalfa had green grass yield of 30800kg/hm2, which is the half of Victoria and Alfalfa 54. Victoria and WL324 had the highest dry grass yield of 15000kg/hm2, which was 2 times of Guanzhong (7333kg/hm2). Foreign cultivars had higher yield either on green grass or dry grass yield than Guanzhong alfalfa.
3. 22 alfalfa cultivars had significant difference on quality, total crude protein content and every harvest crude protein content. Crude protein content, crude fiber content were agreement with or higher than international first grade dry grass product standard. Defy, WL323HQ had the crude protein content of 23%. Guanzhong alfalfa had the crude protein of 20.75% and crude fiber content of 16%.
4. 22 alfalfa cultivars had insignificant difference on transpiration rate and stomal conduct rate. But photosynthesis rate, inter cellular CO2 concentration, instant water use efficiency (WUE) and canopy temperature were significant. Victoria, WL323ML, WL252HQ had higher instant water use efficiency, WUE of Guanzhong alfalfa was 3 u mol/mol. Hay grazer, Sitel had higher canopy temperature which indicated that they aged quickly. Queen, Amerigraze had lower canopy temperature, which indicated that grass layer had sharp metabolism, higher hot resistance, and aged slowly.
5. Evaluated 22 alfalfa cultivars synthetically, Victoria, Total, WL252HQ, Alfalfa 54 had the grades of more than 37.5(total 50 grades). Guanzhong alfalfa had 28.5 grades, (less than 30). Synthetically Application should choose higher grades cultivars. If single destination was chased or uses them as breeding material, only some higher grades index of the cultivars should be chosen, considered them synthetically is not necessary.
引文
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