Genetic improvement of fruit quality traits in starfruit (Averrhoa carambola) hybrids

Fruit quality performance of 12 selected F1 hybrid starfruits from a hybridisation programme were evaluated at MARDI Kluang Station, Johor, Malaysia. Four commercial and registered clones (‘B10’, ‘B17’, ‘B11’ and ‘B2’) that were used as parents were also planted as controls. Seven fruit quality traits were recorded and analysed. Results showed that six fruit quality traits, namely, fruit weight, fruit length, fruit width, wing width, wing length and total soluble solids content were highly significantly different among the treatments except for one parameter (number of seeds per fruit) that was only significant different. Trait number of seeds per fruit was also significantly different among treatments. However, there was no significant difference between replications. Results also showed no wide variation in the fruit quality traits in hybrids except for the number of seeds per fruit (CV - 38.04%) as starfruit is a cross-pollinated crop. Among the treatments, hybrid 1711-24 showed the highest TSS and medium fruit size as compared to the parents. Based on preliminary water content (juiciness) analysis, hybrid 1711-24 (88.7 g/100 g) had a comparable juice content with parent ‘B17’ (84.6 g/100 g) which had the lowest juice content. Thus, hybrid 1711-24 has good eating quality as it is less juicy since starfruit contains too much water. Vitamin C content was highest in hybrid 1711-24 (32.2 mg/100 g) as compared to the parents. Overall, the hybrids showed significant improvement of fruit quality traits as compared to the parents. Hybrid 1711-24 has the potential to become a commercial clone as it has higher TSS and vitamin C content, less water content and medium in fruit size as compared to export clone ‘B10’. This fruit size character is good for export market because it can increase the number of fruits per box in transportation.