Study On Evaluation System In New Combination Of Fresh-eating Waxy Corn

Screening and evaluation of new combinations was a important link during the new variety breeding of fresh-eating waxy corn. In order to screening the excellent combination both in the yield and quality,using TNX4001, TNX20115, TNX0802 etc. fresh-eating waxy corn as the experimental materials, through investigating fresh ear yield and quality,an evaluation index system of fresh-eating waxy corn was set up.Based on the field experiment, agronomic characters related to yield, such as: plant height, ear height, bare plant rate, plant type,disease resistance, insect resistance and lodging resistance were surveyed. The commodity quality was observed during fresh ear harvest time; After fresh ear cooked, were tased the fragrance, pericarp thickness, tenderness of kernel, viscosity, sweetness and the fresh-eating quality was evaluated by multi-factors comprehensive appraisal technique. Meanwhile, the suitable harvest time was determined by drawing the curve of dry weight and water content rate.The results showed that plant height, ear height, bare plant rate, plant type, dsease rsistance, insect resistance, lodging resistance affected yield; Fresh-ear type, arrangement uniformity of kernel, plumpness of kernel, barren ear tip, insect bite, injury, fragrance, pericarp thickness, tenderness of kernel, viscosity, sweetness affected quality.This system consisted of 2 first grade indexes, 4 second grade indexes and 17 third grade indexes. The evaluation index system of the combinations of fresh-eating waxy corn was as follows: the first grade index included: fresh ear yield≥12000kg/hm2, and high quality of fresh earl. the second grade index included: good agronomic characters, strong stress resistance, good commodity quality and eating quality. the third index included: no bare plant, half compact or compact plant type, no disease, no insect, lodging percentage < 5%, eating quality comprehensive appraisal score≥0.44, moderate plant height(192～251cm) and ear height(59～114cm), uniform fresh ear type, arrangement uniformity of kernel, hight grain plumpness, barren ear tip≤2cm, no insect bite and injury ear, hight fragrance(average score:5.94), thin pericarp(average score:6.12),, kernel tenella(average score:6.34), moderate viscosity(average score:5.96) sweet(average score:5.64).