■甜叶菊是一种多年生草本植物,在全球范围内广泛用作天然甜味剂。负责其甜味的关键化合物包括甜菊苷和莱鲍迪甙A。为了改善这些甜菊醇糖苷,本研究是为了研究诱变对生长参数的影响,使用十种剂量的伽马射线(5-100kR)在甜叶菊中的甜菊醇糖苷和核DNA含量。
■甜叶菊“Madhuguna”品种的健康种子在甜叶菊育种场开发和维护,农业技术部,CSIR-喜马拉雅生物资源技术研究所,Palampur(HP),印度接受了从5kR到100kR的十种剂量的伽马射线(每个600种子/剂量)的辐照(即,5、10、15、20、30、40、50、60、80和100kR)使用CCS哈里亚纳邦农业大学的Co60伽马辐照室,希萨尔,(哈里亚纳邦),印度。
■记录了所有研究的幼苗性状的显着变化,而在达到子叶期后对幼苗的主要影响,并且超过40kR的剂量表明幼苗的绝对死亡率。根据概率分析,最佳LD50剂量在20-23kR范围内。使用高效液相色谱法对296个突变体进行的糖苷分析显示,随着辐射剂量的增加,总甜菊醇糖苷含量降低。剂量为5kR和10kR,被发现在增加总糖苷含量方面是有效的。还针对增加的莱鲍迪甙-A甜菊苷比率筛选了总共72个有希望的突变体。使用流式细胞术比较核DNA含量显示,随着伽马射线剂量的增加,总核DNA含量也有类似的下降。与对照中的2.72yg相比,在5、10、15、20和30kR处理下的平均基因组大小为2.72、2.69、2.68、2.70和2.66yg。
■发现甜叶菊中的温和剂量的伽马射线(5和10kR)在提高平均甜菊醇糖苷含量方面是有效的,并且可以用于未来的甜叶菊突变程序中。
UNASSIGNED: Stevia rebaudiana Bertoni is a perennial herb, widely used as a natural sweetener around the globe. The key compounds responsible for its sweetness includes stevioside and rebaudioside-A. In order to improve these steviol glycosides, the present study was initiated to study the effect of induced mutagenesis on growth parameters, steviol glycosides and nuclear DNA content in
Stevia rebaudiana Bertoni using ten doses of gamma-rays (5-100 kR).
UNASSIGNED: Healthy seeds of \'Madhuguna\' variety of
Stevia rebaudiana Bertoni developed and maintained at
stevia breeding farm, Agrotechnology division, CSIR-Institute of Himalayan Bioresource Technology, Palampur (HP), India were irradiated with ten doses of gamma rays (600 seeds each/dose) ranging from 5 kR to 100 kR (i.e., 5, 10, 15, 20, 30, 40, 50, 60, 80 and 100 kR) using Co60 gamma irradiation chamber at CCS Haryana Agricultural University, Hisar, (Haryana), India.
UNASSIGNED: Significant variations were recorded for all the seedling traits studied while major impact was noticed on the seedling after reaching the cotyledonary stage and doses above 40 kR showed absolute mortality of the seedlings. Based on probit analysis, the optimum LD50 dose lies in the range of 20-23 kR. Glycosidic profiling of 296 mutants using high-performance liquid chromatography showed decreased total steviol glycoside content with increased radiation dose. Doses 5 kR and 10 kR, were found to be effective in increasing the overall glycosidic content. A total of 72 promising mutants were also screened for increased rebaudioside-A stevioside ratio. Comparison of nuclear DNA content using flow cytometry revealed a similar decrease in the total nuclear DNA content with increase in dosage of gamma rays. The average genome size at 5, 10, 15, 20 and 30 kR treatments were 2.72, 2.69, 2.68, 2.70 and 2.66 pg as compared to 2.72 pg in control.
UNASSIGNED: Mild dose of gamma rays (5 and 10 kR) in stevia were found to be effective in improving the mean steviol glycoside content and may be used in future
stevia mutation programmes.