Raji R, Siril E A
Department of Botany, University of Kerala, Kariavattom, Trivandrum, 695581 India.
Physiol Mol Biol Plants. 2021 Feb;27(2):429-443. doi: 10.1007/s12298-021-00955-x. Epub 2021 Feb 19.
is a fruit tree able to propagate through conventional vegetative means to a limited extent restricts its wide cultivation by the farmers. In the present report, we have developed an efficient in vitro propagation protocol using mature nodal explants from a 17-year-old tree for the first time with 6.6 shoots/culture. Explants cultured on agar (0.8%) gelled standard Murashige and Skoog (MS) medium, ½ MS, ¾ MS, White's, Gamborg's B or woody plant medium (WPM) supplemented with 2.5 µM benzyl adenine (BA) and 0.1 µM α-naphthalene acetic acid (NAA) showed the superiority of ½ MS medium in terms of explant response and number shoots (6.6). Further optimization of ½ MS medium by altering nutrient elements (macros, micros, vitamins and Fe EDTA) were undertaken, and MS medium composed of half-strength major salts, original strength of minor salts and vitamins were supplemented with BA (2.5 µM) and NAA (0.1 µM), produced enhanced axillary bud proliferation (8.88/explant) and shoot elongation (3.83 cm). Reculturing of original explant on this medium after IV passages produced more than 16 healthy shoots per culture which attained a length of 4.13 cm. Microshoots raised through this way were rooted (86.11%) ex vitro by pulse treatment with 2 mM indole-3-butyric acid (IBA) for 5 min followed by planting in nursery pots containing a 1:1:1 (v/v/v) mix of sand, soil, and farmyard manure. The hardened plants were successfully planted in the fruit tree garden of the Department. Genetic fidelity of micropropagated and mother plants were tested using random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers which showed a high degree of monomorphism thus supported morphological uniformity of micropropagated plants.
一种果树若只能通过传统营养繁殖方式进行有限程度的繁殖,这会限制农民对其进行广泛种植。在本报告中,我们首次利用一棵17年树龄的树的成熟节段外植体,开发出了一种高效的离体繁殖方案,每个培养物可产生6.6个芽。将外植体培养在添加了2.5 μM苄基腺嘌呤(BA)和0.1 μM α-萘乙酸(NAA)的琼脂(0.8%)凝胶化标准Murashige和Skoog(MS)培养基、1/2 MS培养基、3/4 MS培养基、White培养基、Gamborg's B培养基或木本植物培养基(WPM)上,结果显示1/2 MS培养基在外植体反应和芽数量(6.6个)方面具有优势。通过改变营养元素(大量元素、微量元素、维生素和铁螯合物)对1/2 MS培养基进行了进一步优化,由半量主要盐类、原强度的微量元素和维生素组成的MS培养基,添加BA(2.5 μM)和NAA(0.1 μM)后,腋芽增殖增强(每个外植体8.88个),芽伸长(3.83厘米)。在IV次继代培养后,将原始外植体重新接种到该培养基上,每个培养物可产生超过16个健康芽,芽长达到4.13厘米。通过这种方式产生的微芽通过用2 mM吲哚-3-丁酸(IBA)脉冲处理5分钟,然后种植在含有沙子、土壤和农家肥1:1:1(v/v/v)混合物的育苗盆中,在离体条件下生根(86.11%)。炼苗后的植株成功种植在该部门的果园中。使用随机扩增多态性DNA(RAPD)和简单序列重复区间(ISSR)标记对微繁殖植株和母株的遗传稳定性进行了测试,结果显示高度单态性,从而支持了微繁殖植株的形态一致性。