포장에서 교잡종 옥수수의 도복과 수분스트레스간의 관계
포장조건에서 22종의 옥수수교잡종을 과습조건에서 도복관련형질들의 상호관련성을 검정하였는데 좌절중 (1.0 m, 1.5 m)과 좌절부위등을 평가하였고 주요한 도복 저항성 형질인 좌절중, 간직경, 뿌리건물중, 중심고등의 상호 관련성을 함께 평가하였다. 본시험은 포트시험에서 일차 스크린 한 것을 논에 경사지를 만들어 경사지별로 수분함량과 도복저항성을 비교하기 위하여 관수시기(과습조건)를 파종후 20일, 5엽기, 출웅기, 출사기로 구분하였고 관수량은 100 mm/일 씩 5일간 처리하였으며 조사는 수확기에 수행 하였다.
본시험의 결과 출사기에 1.0 m, 1.5 m 높이에서 좌절중과 중심고는 정의 상관을 보였으며 파종후 20일차에 관수처리구에서는1.0m, 1.5m 모두 좌절강도와 간직경이 정의 상관을 나타냈다. 관수처리 5엽기에서는 높이 1.0 m에서 좌절강도와 간직경간의 강한 정의 상관을 나타냈으며 도복관련 형질인 간직경, 뿌리건물중,지상부 중심고, 좌절중, 좌절고등이지만 관수처리시 이들을 가장쉽게 판별 할 수 있는 방법은 5엽기에 관수처리구가 가장 효율적으로 사료된다.
Under field conditions, 22 corn hybrids(CHs) were tested for several characteristics related to lodging resistance and excessive water stress, such as pushing resistance on 1.0 and 1.5 m hights of the corns and breaking point. The 22 corn CHs were selected because they showed strongest pushing resistance and breaking resistance of culm as well as the highest thickness of basal culm, leaf greenness, leaf area, and plant height based on two pre-pot experiments performed in phytotron. To make excess water condition, water irrigation was done at 1) 20-d after seeding, 2) 5th leaf stage, 3) tasseling stage, and 4) silking stage with 100 mm/day for 5 days. Lodging-related characteristics were measured: culm diameter, root dry weight, weight balance of above-ground plant, breaking resistance, and breaking height in field experiment. Among all the characteristics tested, we explained in the two critical points for lodging resistance: 1) breaking resistance and breaking point, 2) culm diameter with breaking resistance and breaking point, and they were further evaluated for the relationships with the 1.0 and 1.5m height of above-ground plant. In the corn hybrids, there was a positive correlation between breaking resistant and weight balance of corn at the silking stage water treatment at 1.0 and 1.5-m height. And breaking resistant and culm diameter had a positive relationship at the 20-d water treatment at both measuring height. In conclusion, selection for lodging resistant hybrids or germplasms to excess soilwater should be made at the 5th leaf stage water treatment, and basal culm thickness should be considered to evaluate the resistance of the corn hybrid plants to lodging.