Krishna Hare, Alizadeh Mahdi, Singh Dhurendra, Singh Udayvir, Chauhan Nitesh, Eftekhari Maliheh, Sadh Radha Kishan
ICAR-Central Institute for Arid Horticulture, Beechwal, Bikaner, Rajasthan, 334 006, India.
Department of Horticulture, Faculty of Agriculture, Gorgan University of Agricultural Sciences and Natural Resources (GUASNR), Golestan, Gorgan, Iran.
3 Biotech. 2016 Jun;6(1):54. doi: 10.1007/s13205-016-0389-7. Epub 2016 Feb 13.
The advancements made in tissue culture techniques has made it possible to regenerate various horticultural species in vitro as micropropagation protocols for commercial scale multiplication are available for a wide range of crops. Clonal propagation and preservation of elite genotypes, selected for their superior characteristics, require high degree of genetic uniformity amongst the regenerated plants. However, plant tissue culture may generate genetic variability, i.e., somaclonal variations as a result of gene mutation or changes in epigenetic marks. The occurrence of subtle somaclonal variation is a drawback for both in vitro cloning as well as germplasm preservation. Therefore, it is of immense significance to assure the genetic uniformity of in vitro raised plants at an early stage. Several strategies have been followed to ascertain the genetic fidelity of the in vitro raised progenies comprising morpho-physiological, biochemical, cytological and DNA-based molecular markers approaches. Somaclonal variation can pose a serious problem in any micropropagation program, where it is highly desirable to produce true-to-type plant material. On the other hand, somaclonal variation has provided a new and alternative tool to the breeders for obtaining genetic variability relatively rapidly and without sophisticated technology in horticultural crops, which are either difficult to breed or have narrow genetic base. In the present paper, sources of variations induced during tissue culture cycle and strategies to ascertain and confirm genetic fidelity in a variety of in vitro raised plantlets and potential application of variants in horticultural crop improvement are reviewed.
组织培养技术的进步使得在体外再生各种园艺物种成为可能，因为针对多种作物都有商业化规模繁殖的微繁殖方案。为其优良特性而选择的优良基因型的克隆繁殖和保存，要求再生植株之间具有高度的遗传一致性。然而，植物组织培养可能会产生遗传变异，即由于基因突变或表观遗传标记的变化而产生体细胞克隆变异。细微体细胞克隆变异的出现对于体外克隆和种质保存来说都是一个缺点。因此，在早期确保体外培养植株的遗传一致性具有极其重要的意义。人们采用了多种策略来确定体外培养后代的遗传保真度，包括形态生理、生化、细胞学和基于DNA的分子标记方法。在任何微繁殖计划中，体细胞克隆变异都可能构成严重问题，在这些计划中非常需要生产出与原品种一致的植物材料。另一方面，体细胞克隆变异为育种者提供了一种新的替代工具，使他们能够在园艺作物中相对快速地获得遗传变异，而无需复杂技术，这些园艺作物要么难以育种，要么遗传基础狭窄。本文综述了组织培养周期中诱导变异产生的来源、确定和确认各种体外培养幼苗遗传保真度的策略以及变异体在园艺作物改良中的潜在应用。
