Journal of Bio-Environment Control ISSN:1229-4675(Print) 2765-3641(Online) 생물환경조절학회지

This study was carried out to investigate proper stem cutting position and air temperature to regenerate roots from cuttings of bitter gourd. ‘NS454’ (NS) and ‘Dragon’ (DR) cultivars were tested and the cutting position was cut at the 3rd node in the stem (treatment I) and cut at the central part (stem segment) between 3rd leaf and 4th leaf in the stem (treatment II). The air temperature was maintained at 18, 23, 28 and 35^oC in the growth chambers, respectively. The photosynthetic photon flux at the ground of a chamber was maintained in approximately 150- 200 μmol m^-2 s^-1 during the 16-hour photoperiod. The relative humidity in the chambers was maintained over 85%. After 10 days of cuttings, regardless of cutting position, DR and NS cultivars showed 100% the survival rate in the 18^oC or 23^oC treatments, however, most of plants 18^oC treatment had not rooting. In the 28^oC treatment, regardless of cutting position, DR and NS cultivars showed 100% of the rooting rate. In the 23^oC treatment, for DR cultivar, the node cutting showed 90% of rooting rate and the stem segment cutting showed 40% rooting rate. For NS cultivar, the node cutting showed 50% of rooting rate and the stem segment cutting showed 40% rooting rate. DR and NS cultivars have high rooting rate, while the rooting rate remarkably decreased in the 35^oC treatment. For DR cultivar, the stem segment cutting showed 5.3 of the highest rooting number and the node cutting showed 2.7 rooting number in the 28^oC treatment. NS cultivar was not significantly different the rooting regardless of cutting position. The results suggested that cutting at the stem segment cutting of bitter gourd is an effective cutting method for increasing survival rate and the air temperature should be maintained at 28^oC.