The aim of this study was to assess the effect of long-term in vitro sub-culturing on the varietal degeneration of three sweet potato varieties, namely, Monate, Mokone and Ndou which were sub-cultured for 32, 23 and 1...The aim of this study was to assess the effect of long-term in vitro sub-culturing on the varietal degeneration of three sweet potato varieties, namely, Monate, Mokone and Ndou which were sub-cultured for 32, 23 and 12 generations, respectively. Each generation was cultured in a media which is made from 4.43 g/L Murashige and Skoog (MS), 30 g/L sucrose and 2 g/L gelrite, respectively, and grown under 16 h light and 8 h dark photoperiod for 30 d. For each generation, 45 plantlets were acclimatized for two months in a glasshouse. Data on in vitro growth performance and 11 morphological characteristics during acclimatization were recorded. Early root and shoot formation was observed after the 27th and 21st sub-cultured generations of Monate and Mokone, respectively. During acclimatization, plantlets from the same variety showed differences in morphological traits such as leaf colour, abaxial leaf pigmentation, vine pigmentation, petiole pigmentation, leaf wrinkling and flowering. However, the rate of these morphological differences is random and irrespective to increase in sub-culturing. Therefore, to understand the genetic base of these morphological variability, two plantlets from each variety were subjected to genetic analysis by using five simple sequence repeat (SSR) primers (IB-242, IB-318, IB-255F, 1B-248 and IB-255). Although SSR loci IB-255F and IB-318 could distinguish between the three varieties, there were no allelic polymorphisms detected in plantlets from the same varieties. Therefore, long-term sub-culturing do not leads to quality degeneration in the three sweet potato varieties.展开更多
文摘The aim of this study was to assess the effect of long-term in vitro sub-culturing on the varietal degeneration of three sweet potato varieties, namely, Monate, Mokone and Ndou which were sub-cultured for 32, 23 and 12 generations, respectively. Each generation was cultured in a media which is made from 4.43 g/L Murashige and Skoog (MS), 30 g/L sucrose and 2 g/L gelrite, respectively, and grown under 16 h light and 8 h dark photoperiod for 30 d. For each generation, 45 plantlets were acclimatized for two months in a glasshouse. Data on in vitro growth performance and 11 morphological characteristics during acclimatization were recorded. Early root and shoot formation was observed after the 27th and 21st sub-cultured generations of Monate and Mokone, respectively. During acclimatization, plantlets from the same variety showed differences in morphological traits such as leaf colour, abaxial leaf pigmentation, vine pigmentation, petiole pigmentation, leaf wrinkling and flowering. However, the rate of these morphological differences is random and irrespective to increase in sub-culturing. Therefore, to understand the genetic base of these morphological variability, two plantlets from each variety were subjected to genetic analysis by using five simple sequence repeat (SSR) primers (IB-242, IB-318, IB-255F, 1B-248 and IB-255). Although SSR loci IB-255F and IB-318 could distinguish between the three varieties, there were no allelic polymorphisms detected in plantlets from the same varieties. Therefore, long-term sub-culturing do not leads to quality degeneration in the three sweet potato varieties.