Analysis Of Agronomy, Quality Characters And Esterase Isozyme Of North American Cultivated Barley

Barley (Hordeum vulgare Linn.) is a crop of gramineae, triticeae, and hordenm, and it is an annual or biannual wheat crop. Barley has strong stress resistances, wide range of cultivating area, it and has a special status and role in crop cultivation and farming. Many researches have been carried out on resources of domestic and foreign barley germplasm. However, barley's production in country has decreased year by year. The supply is not adequate for the demand, and the malting qualities should be improved urgently. American beer barley has excellent qualities, and Canadian beer barley is of high reputation. Therefore, through proceeding identification and evaluation on foreign barley breed, excellent resources can screened out. This study is about systemic researches of 99 barley breeds colleted from North America(America and Canada). It is mainly about the investigation, determination and evaluation of agronomic characters and quality characters, and the analysis of electrophoresis pattern of esterase isozyme. Through the analysis of correlation, diversity and clustering we hope to evaluate the genetic diversities, and screen out breeds with excellent characters. Then we collect materials and provide evidences for the modifying and breeding works of barley of our country. The main results of this paper were as follows:1.Investigation of agronomic characters:For the average value of plant height is 98.45 cm, distribution range is 77.54 cm～123.22 cm. For spike number per plant, average value is 10.17, distribution range is 6.8～15.8. For spike length, average value is 9.82 cm, distribution range is 7.40 cm～12.52 cm. For spikelet number, average value is 29.71, distribution range is 16～36.6. For grain number per spike, average value is 47.06, distribution range is 23～86, it has the largest variation. For 1000-grain weight, average value is 35.99 g, distribution range was 17.61 g～47.32 g. For ear bearing tiller percentage, average value is 80.81%, distribution range is 53.13%～98.33%. The results indicates that, the most cultivars are mid-height type, there are no dwarf materials. The stooling is strong. The spike length is of or above mid-length. There are more spikelets. The grain number per spike is low. The 1000-grain weight and ear bearing tiller percentage are high. Eighteen(ten two-rowed and eight six-rowed barley) elite cultivars with excellent agronomic performances are screened out.2.Determination of quality characters:For protein content, the average value is 13.10%, variation amplitude is 9.94%～17.99%. For lysine content, average value is 0.47%, variation amplitude is 0.38%～0.61%. For amylon content, average value is 49.92%, variation amplitude is 40.02%～63.47%. For amylose content, average value is 24.87%, variation amplitude is 0.00%～31.32%. For amylopectin content, average value is 25.05%, variation amplitude is 9.27%～55.32%. The experiment results indicates that, the most cultivars are with moderate or high protein content, high lysine content, moderate amylon content. Thirteen(eight two-rowed and five six-rowed barley) elite cultivars with excellent quality performances and two waxy barley are screened out.3.Determination of amylase activity:the variation range ofα-amylase activity is 2.15 mg/g·min-1～63.05 mg/g·min-1, average value is 19.39 mg/g·min-1. Most materials'α-amylase activity are less than 25 mg/g·min-1, amounting to 70.70%. The variation range ofβ-amylase activity is 16.20 mg/g·min-1～677.20 mg/g·min-1, average value is 327.28 mg/g·min-1.β-amylase activity is mainly distributed during 250 mg/g·min-1 to 500 mg/g·min-1, amounting to 72.72%. Results show thatβ-amylase activity is higher thanα-amylase activity. Nine high amylase activity cultivars (two was highα-amylase activity cultivars and seven was highβ-amylase activity cultivars) are screened out.4.Analysis of correlativity:according to the correlation coefficients among agronomic characters, plant height and 1000-grain weight are the most significant characters. If the two characters are improved, the yield can be increased. But improving plant height will easily cause lodging. Therefore, we can increase the yield only through improving the 1000-grain weight. The correlation analysis of quality characters shows that protein content has very high relevance with lysine content, but very notable negative relevance with amylon content, and very notable relevance with (3-amylase activity. So, protein content is the most important controlling factor of the quality characters. And 1000-grain weight has very notable negative relevance with protein content. Therefore,1000-grain weight can be used as the first visualized character to inspect when screening excellent resources.5.The electrophoresis pattern of esterase isozyme shows eleven bands in all. Among those, five bands are mutual bands that all materials have. The polymorphism of the bands is 54.54%. According to the mobility, the electrophoresis bands can be divided into three sections:Section A, Section B and Section C. All the materials show eight zymogram types. The two-rowed materials show four types in all, and the six-rowed materials show six types. The zymogram of two-rowed and six-rowed materials s quite different. Two-rowed barley are mainly in typeⅠ, and six-rowed barley are mainly in typeⅡ. Six-rowed materials' zymogram is more complex than two-rowed materials', and there are also differences in the same row type.6.Clustering analysis indicates:similar conclusion can be reached between clustering analysis of agronomic characters and that of isozymes. Most two-rowed and six-rowed materials are in different categories, which shows that agronomic characters and the zymogram of esterase isozyme have close relationship with row type. The integrative clustering of agronomic, quality and amylase activity show:materials with excellent or special performances are far away from others, and gathered together respectively. This objectively reflects the differences among all characters of the materials.7.Variety index analysis:the variety indices of agronomic characters, quality characters and amylase activities indicate that ear bearing tiller percentage's variety index is the lowest, which is 0.789. The second lowest is amylose, which is 1.561. Other characters' indices are higher, about 2, which indicates that these characters have abundant variation, and can offer abundant parental materials for barley breeding for our country.