Effect of different LED lights spectrum on the in vitro germination of gac seed (Momordica cochinchinensis)

Momordica cochinchinensis, also known as gac, is an indigenous fruit that can commonly found in Southeast Asia. Studies had shown that M. cochinchinensis contained a higher level of carotenoids, β-carotene, and lycopene compared to other vegetables and fruits. The present study was conducted to study the effect of light conditions on gac seeds germination and effect of light-emitting diode (LED) spectra (violet, blue, green, and red) on shoot, root, and leaf formation from germinated gac seeds. A total of 60 surface sterilised uncoated gac seeds were cultured in MS media where half of them exposed to sunlight while another half kept in the enclosed cupboard. Germinated seeds were then transferred to new MS media which contained 1 mg/L of BAP and cultured under different LED lights. Gac seeds germinated well in 12 hours light treatment at the rate of 75% after one week while dark treated seeds did not germinate at all. The green LED light spectrum was the most effective for the production of the highest mean number of shoots at 4.75 ± 0.63. On the other hand, the violet LED was the most effective spectrum in producing the highest number of roots, which was 7.50 ± 0.58. Meanwhile green LED produced the highest root length of 6.25 ± 0.25 cm. Besides, green LED treatment also able to induce the highest number of leaves, which was 10.21 ± 1.89. Lateral shoot and tendrils were developed on blue LED spectrum treated seed. In conclusion, light facilitates gac seed germination while the green LED light induced better characteristics of gac plant.