Micro-Tuber Production in Diploid and Tetraploid Potato after Gamma Irradiation of &amp;lt;i&amp;gt;in Vitro&amp;lt;/i&amp;gt; Cuttings for Mutation Induction

Souleymane Bado,Margit Laimer,Abdelbagi Mukhtar Ali Ghanim,Enoch Sapey,Ndiogou Gueye,Vivian Carol Blok,Ndeye Fatou Deme,Brian Peter Forster

doi:10.4236/ajps.2016.714173

Abstract

Micro-tubers are important propagules in potato breeding and potato production, and they are also dormant and easily transported and therefore good targets for mutation induction in potato mutation breeding. A prerequisite for mutation breeding is to determine optimal mutation treatments. Therefore, radio-sensitivity tests of a tetraploid and a diploid potato to gamma irradiation were undertaken. Effects of different gamma sources on radio-activity were also studied. In vitro potato cuttings were gamma irradiated using a wide dose range (0, 3, 6, 9, 12, 15 and 20 Gy). The irradiated cuttings were then cultured to induce micro-tubers directly in vitro. Micro-tuber morphotypes were assessed after irradiation of cuttings using three gamma sources with emission activities of 1.8, 7.07 and 139 Gy/min. The diploid species (Solanum verrucosum) was more radio-sensitive than the tetraploid cultivar Desirée (Solanum tuberosum). Gamma dose rates had significant influences on subsequent micro-tuber production at various mutant generations. Effects included reductions in the number, size and weight of micro-tubers produced. Gamma dose was more lethal for the diploid potato genotype and micro-tubers produced were small compared to those produced by the tetraploid genotype after irradiation. Different treatments are recommended for diploid and tetraploid potato irradiation in producing large mutant micro-tuber populations. The mutant micro-tuber populations may then be screened for interesting mutations/trait for both genetics and plant breeding purposes.

Highlights

Potato (Solanum spp.) is the most important non-cereal crop worldwide and ranks the fourth after maize, rice and wheat [1]
We describe the effects of gamma irradiation treatments on in vitro micro-cuttings and the subsequent development of mutant micro-tuber populations which may be tested for new traits such as cyst nematode resistance; mutant populations in the form of micro-tubers provide convenient starting materials for researchers and growers
Exposure time duction of micro-tubers started in the first week of incubation in the tetraploid S. tuberosum cv

Summary

Introduction

Potato (Solanum spp.) is the most important non-cereal crop worldwide and ranks the fourth after maize, rice and wheat [1]. Potato production faces major challenges including low multiplication rates in the field under conventional (biological) seed production and yield losses due to susceptibilities to diseases and pests such as late blight disease, potato cyst nematode and Colorado beetle [2]-[6]. Many traditional cultivars suffer from poor yield with reduced tuber size and carry undesirable traits, such as sunken eyes, susceptible to blight disease and cyst nematodes, which result in reduced yield and quality. Improvements of potato by breeding are hampered by local preferences for old traditional cultivars in many parts of the world. Despite the large germplasm resources, success in breeding new cultivars has been slow and genetic variability among elite lines is narrow. The narrowing of the genetic base of commercial cultivars is a primary cause of stagnation in yield improvement [10]

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Discussion

Conclusion