Ahmad Naseem, Fatima Nigar, Faisal Mohammad, Alatar Abdulrahman A, Pathirana Ranjith
Plant Biotechnology Laboratory, Department of Botany, Aligarh Muslim University, Aligarh 202002, India.
Department of Botany & Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia.
Plants (Basel). 2022 Apr 26;11(9):1163. doi: 10.3390/plants11091163.
An improved and stable micropropagation system using the cytokinin, -Topolin (N6 (3-hydroxybenzylamino purine-T), with nodal explants in L. was established. Among the different doses of T, the maximum number of shoots with the highest shoot length was obtained using Murashige and Skoog's (MS) medium supplemented with 5.0 µM T. The results were consistent throughout the proliferation period, when recorded at week 4, 8, and 12 of being cultured, with an average of 16.4 shoots per nodal explant, and having a mean length of 4.10 cm at week 8. Shoot proliferation rates could be further improved by a combination of 5.0 µM T with 0.5 µM α-naphthalene acetic acid in MS medium; nodal explants produced an average of 24.3 shoots with a mean length of 5.74 cm after 8 weeks of being cultured. Among the five different concentrations of three auxins tested for the rooting of microshoots in MS medium, a 1.0 µM indole-3-butyric acid treatment was the best, with an average of 10.3 roots per microshoot at an average length of 3.56 cm in 93% of microshoots within 4 weeks of being transferred to this medium. A significant reduction of both chlorophyll a and b in leaves during the first week of acclimation corresponded with a high accumulation of malondialdehyde (MDH), indicating that lipid peroxidation affected chlorophyll pigments. From the second week of acclimation, photosynthetic pigment content significantly increased and MDH content decreased. The net photosynthetic rate and leaf carotenoid content showed almost linear increases throughout the acclimation period. Activity of antioxidant enzymes, namely, superoxide dismutase, catalase, and peroxidases, consistently increased throughout the acclimation period, corresponding with the accumulation of photosynthetic pigments, thus demonstrating the role of the improved antioxidant enzymatic defense system during acclimation. A comparison of parent plant DNA with that of the greenhouse acclimated plants using random amplified polymorphic DNA and inter-simple sequence repeat markers showed a monomorphic pattern indicating genetic stability and the suitability of the method for micropropagation of .
建立了一种改良的、稳定的微繁殖系统，该系统使用细胞分裂素-托布津（N6-(3-羟基苄基氨基嘌呤-T)），以L.的茎节外植体为材料。在不同剂量的托布津中，使用添加了5.0 μM托布津的Murashige和Skoog（MS）培养基获得了最多数量且茎长最长的芽。在培养的第4周、第8周和第12周记录时，整个增殖期的结果是一致的，每个茎节外植体平均有16.4个芽，在第8周时平均长度为4.10厘米。在MS培养基中，将5.0 μM托布津与0.5 μM α-萘乙酸组合可进一步提高芽的增殖率；茎节外植体在培养8周后平均产生24.3个芽，平均长度为5.74厘米。在MS培养基中测试的用于微芽生根的三种生长素的五种不同浓度中，1.0 μM吲哚-3-丁酸处理效果最佳，在转移到该培养基4周内，93%的微芽平均每个微芽有10.3条根，平均长度为3.56厘米。驯化第一周叶片中叶绿素a和b均显著减少，同时丙二醛（MDH）大量积累，表明脂质过氧化影响了叶绿素色素。从驯化第二周开始，光合色素含量显著增加，MDH含量下降。在整个驯化期，净光合速率和叶片类胡萝卜素含量几乎呈线性增加。抗氧化酶即超氧化物歧化酶、过氧化氢酶和过氧化物酶的活性在整个驯化期持续增加，与光合色素的积累相对应，从而证明了改良的抗氧化酶防御系统在驯化过程中的作用。使用随机扩增多态性DNA和简单序列重复区间标记对亲本植物DNA与温室驯化植物的DNA进行比较，结果显示为单态模式，表明遗传稳定性以及该方法对L.微繁殖的适用性。
