콩 재배종과 야생종 유전자원의 엽 형질 변이

Abstract

Although leaf characters are important in soybean [Glycin max (L.) Merr.] breeding and development of cultural methods, very little information has been reported. The objectives of this study were to evaluate and analyze the relationships among leaf characters and suggest possible classification criteria for cultivating and wild (Glycin soja Sieb. & Zucc.) soybeans. Total of 94 cultivating and 91 wild soybean accessions from the Soybean Germplasm Laboratory of Chungbuk National University were used for this study. Central leaflet of the second leaf from the top of the plant was selected to measure leaf characters. Average leaf length, leaf width, leaf area, leaf shape index (LSI) of cultivating and wild soybeans were 12.3±1.25 cm and 6.6±1.35 cm, 6.8±1.241 cm and 2.9±0.92 cm, 55.6±15.75 cm2 and 14.3±7.83 cm2, and 1.9±0.38 and 2.4±0.53, respectively. Based on LSI, three categories of leaf shape, i.e., oval, ovate and lanceolate, were defined as LIS≤2.0, LSI 2.1∼3.0 and 3.1≤LSI, respectively. Percentage of oval, ovate and lanceolate leaf types among cultivating and wild soybean accessions were 78.7%, 17.0% and 4.3 %, and 40%, 15.4% and 4.4%, respectively. Based on leaf length, three categories for cultivating, i.e. short leaf (≤11.0 cm), intermediate (11.1∼13.0 cm), and long (13.1 cm≤), and four categories, i.e. short (≤5.0 cm), intermediate (5.1∼ 7.0 cm), long (7.0∼9.0 cm), and very long (9.1 cm≤) for wild soybeans were defined. Short, intermediate and long leaf types were about 1/3, 1/2 and 1/6, respectively, in cultivating soybeans, and 15.4%, 40.7% and 39.5%, plus 4.4% of very long leaf type in wild soybean. Cultivating and wild soybeans had leaf thickness, leaf area ratio (LAR), angle and petiol length of 0.25±0.054 mm and 0.14±0.032 mm, 40.1±8.22 and 53.7±12.02, 37.6±5.89° and 54.6±10.77°, and 23.9±5.89 cm and 5.9±2.33 cm, respectively. There were highly significant positive correlations between leaf length and leaf width, and negative correlation between LSI and leaf width both in cultivating and wild soybeans. Although leaf area showed significant correlations with leaf length, leaf width and LIS in cultivating soybeans, wild soybeans showed no significant relationships among these characters. In general, soybeans with oval, ovate and lanceolate leaves were significantly different in leaf width and thickness. Cultivating soybean with oval leaf had greater leaf area, while wild soybeans with oval or ovate leaf had longer petiol than with lanceolate leaf.