In Vitro Propagation Of Two Anchote [Coccinia Abyssinica (Lam.) Cogn] Genotypes Using Shoot-Tip Culture

Abstract

Anchote [Coccinia abyssinica (Lam.) Cogn.] is an endemic plant with high calcium content grown for its edible tuberous roots in Ethiopia. It is difficult to produce true-to-type anchote plants to sustain tuber quality through propagation by seeds as the plant pollinates by both self and cross. The study was carried out at Jimma agricultural research center at tissue culture laboratory with the objectives of in vitro propagation of two anchote [Coccinia abyssinica (Lam.) Cogn.] genotypes using shoot-tip culture. A completely randomized design (CRD) in factorial arrangement with five replications was used. The treatments were different concentrations of BAP 0.0,0.5,1.0,1.5,2.0,2.5 and 3.0 mg/l BAP for shoot initiation and 0.0, 0.5, 1.0, 1.5, 2.0, 2.5 mg/l BAP for shoot multiplication were used. While different concentrations of IBA 0.0, 0.5, 1.0, 1.5, 2.0, 2.5mg/l IBA were used for root induction. The result revealed that different concentrations of BAP and IBA significantly influenced (P<0.01) shoot initiation and multiplication as well as root induction traits in both genotypes. The early initiation of shoot was 6.3 days for Desta variety and Acc.24/99 (9.3 days) in MS medium supplemented with 1.0 mg/l BAP and 1.5 mg/l BAP respectively. Besides, the highest percentage of shoot induction 98% of cultured explants was obtained at 1 mg/l BAP for Desta variety and at 1.5 mg/l BAP for Acc.24/99 (90%).The highest number of shoot 10.8 was recorded on MS medium supplemented with 1 mg/l BAP for Desta variety and 9.00 at 1.5 mg/l BAP for Acc.24.The lowest number of shoot was obtained from control (hormone free medium) for both genotypes. The maximum shoot length 7.3 and 5.48 was obtained from medium containing 0.5 mg/l BAP for both genotypes. The maximum number of leaves/shoot 13.0 leaves was recorded in MS medium supplemented with 1.0 mg/l BAP for Desta and 9.8 leaves at 1.5 mg/l for Acc.24/99. Early date of root induction was 6.5 days for Desta and 7.3 days for Acc.24/99 recorded on 0.5 mg/l IBA. Maximum numbers of root 13.20 was recorded on MS medium supplemented with 0.5 mg/l IBA for Desta and 12.1 at 0.5 mg/l IBA for Acc.24/99 and 12.1 and highest root length 7.1 cm and 6.4 cm) were observed on medium containing 1.5 mg/l for both genotypes respectively. Well rooted shoots were transferred to greenhouse and 82.14 % and 73.3 % Desta and Acc.24/99 survived, respectively. Generally, MS medium supplemented with 1.0 mg/l BAP is found to be optimum for shoot initiation and shoot multiplication for Desta variety in rooting experiment, half strength MS medium augmented with 0.5 mg/l IBA was optimum for both genotypes. Moreover, 1.0 mg/l BAP and 1.5 mg/l was found to be the best for shoot initiation and multiplication; whereas, in vitro rooting 0.5mg/l IBA was found to be the best. Since this study focused only on the effect of BAP hormone alone for shoot multiplication, further research is suggested to be done on multiplication performance by using other combination of hormones and by taking other explant sources.