Enhanced in vitro bud sprouting of field-derived grapevine material

Abstract

Improving the in vitro establishment of grapevine buds is important for micropropagation, sanitation programs, and germplasm conservation. Bud sprouting from field material can vary depending on the variety and the composition of the culture media. This study analyzed the in vitro sprouting and rooting of nodal buds from two Vitis vinifera varieties, It18 and It5, grown in four culture media containing two benzyladenine (BA) concentrations (mg·L⁻¹) with or without activated charcoal (2.2BA, 4.4BA, 2.2BACA and 4.4BACA). Data were analyzed using t-Student test (p<0.05). 

The buds were disinfected using a standard protocol, and placed in the four experimental media. After 21 days of culture, we measured sprouting percentage, shoot length, number of leaves, presence of apical necrosis and rooting percentage.

It18 variety reached a percentage of sprouting of 75% in most treatments, with the longest shoots in 4.4BA and without apical necrosis in media containing activated charcoal. In It5 variety, sprouting was about 80% in all treatments, showing the longest shoots in 2.2BACA. Apical necrosis occurred only in media without activated charcoal. Regarding the number of leaves did not show significant differences among the different media in the It18 variety. However, in the It5 variety, significant differences were found between 2.2BA and 2.2BACA, and also between 2.2BA and 4.4BA.

Rooting results indicated that BA alone did not induce roots in either variety (0%), whereas BA combined with activated charcoal (BACA) promoted rooting. In It18, 2.2BACA achieved the highest rooting percentage (67%), followed by 4.4BACA (27%); whereas, in It5, both BACA media reached 18%.

In conclusion, these results suggest that the addition of activated charcoal is a key factor in reducing apical necrosis, promoting rooting and improving the quality of the regenerated material, but its effect on shoot length and sprouting depends on the variety and the BA concentration. These findings might help refine micropropagation protocols and support sanitation programs and the preservation of table grape varieties.