In vitro chromosome doubling of tomato var. Improved Pope (Lycopersicon esculentum Mill) via colchicine

Abstract

Prevailing biotic and abiotic stresses disrupt tomato seedling establishment, which may lead to yield and quality reduction. Colchicine, a common mutagen, prevents the development of microtubules during cell division resulting in chromosome doubling. Doubled chromosome plants have enhanced germination, shoot formation, leaf structure, and fruit size. Hence, in vitro mutation via colchicine was employed on tomato towards improved seedling characteristics for successful establishment. Seeds were treated with 0.05, 0.10, and 0.15% colchicine for four hours in completely randomized design. Seeds were cultured in vitro using Murashige and Skoog medium. Plant height (p < 0.001) was increased by 2.00 cm (SD 0.85) when applied with 0.05% colchicine. A higher dosage (0.10 and 0.15%) generally resulted in shorter plants wherein the shortest plant height was recorded on plants treated with 0.15% colchicine at 5.94 cm (SD 0.12), about half the height compared to plants not treated with colchicine at all. On root length (p < 0.001), all colchicine treated plants produced longer roots with the application of 0.05% colchicine producing the longest roots at 6.58 cm (SD 0.61). On stomata (p < 0.001), size (length and width) was generally increased with colchicine application where 0.05% colchicine application increased stomatal size at 17.99 mm (SD 0.62) and 16.42 mm (SD 0.62), respectively. The same was also recorded on chromosome size (p < 0.001) in which length and width was recorded at 21.28 mm (SD 0.66) and 15.20 mm (SD 0.50), respectively when exposed to 0.05% colchicine. Other parameters like percentage of germination and leaf size were also enhanced with the application of colchicine. Taken together, these improved characteristics can be implied to enhance the tomato seedling capacity for better field establishment.