A protocol was developed and standardized for the in vitro clonal propagation of PPR-1, a superior temperate mulberry variety using nodal explants. When the nodal explants of PPR-1 mulberry variety were inoculated onto various concentrations and combinations of cytokinins supplemented media, maximum axillary bud proliferation was obtained on combinational rather than individually supplemented hormonal media. Over all, maximum axillary shoot length (7.2 ± 0.61 cm) and maximum number of leaves per explant (8.1 ± 0.85) was obtained on combinational media of 6 benzylaminopurine (BAP) (1.5 mg/L) and kinetin (2.0 mg/L) after 20 days of culture. On individually supplemented cytokinins hormonal media maximum axillary shoot length (4.7 ± 0.61 and 3.2 ± 0.22 cm) with more number of leaves (7.4 ± 0.16 and 6.0 ± 0.35) per explant was obtained at 1.5 mg/L and 2.0 mg/L concentration of BAP , respectively after 20 days of culture. The proliferated axillary shoots when transferred on to different concentrations of auxins containing rooting media, good response of rooting (100%) was observed on Murashige & Skoog (MS) media supplemented with 2.0 mg/L concentration of indole butyric acid (IBA). The raised plantlets were then hardened using 1 : 1 ratio of vermicompost and soil, then gradually they were acclimatized to field conditions. The survival rate of in vitro raised PPR-1 plantlets in field conditions is about 70%.

中文翻译：

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PPR-1（一种优良的温带桑树品种）的体外克隆繁殖

制定了协议并进行了体外标准化PPR-1的无性繁殖，这是使用结节外植体的优良温带桑树品种。当将PPR-1桑树的节点外植体接种到各种浓度和细胞分裂素补充培养基的组合中时，在组合而非单独补充的激素培养基上可获得最大的腋芽增殖。总体而言，在6种苄基氨基嘌呤（BAP）（1.5 mg / L）和激动素（2.0 mg / L）的混合培养基上可获得最大腋生芽长度（7.2±0.61 cm）和每株外植体的最大叶数（8.1±0.85）。经过20天的培养。在1.5 mg / L和2.0 mg / L浓度的外植体上，在单独补充的细胞分裂素激素介质中，每个外植体的最大腋生芽长（4.7±0.61和3.2±0.22 cm）以及更多的叶片数（7.4±0.16和6.0±0.35）。 BAP 培养20天后。当转移到不同浓度的含有生根培养基的植物生长素时，增殖的腋生芽，在补充了2.0 mg / L吲哚丁酸（IBA）的Murashige＆Skoog（MS）培养基上，观察到了良好的生根响应（100％）。然后用ver麦和土壤的比例为1：1来硬化育苗，然后使其逐渐适应田间条件。成活率 然后逐渐使它们适应野外条件。成活率 然后逐渐使它们适应野外条件。成活率在田间条件下，体外培养的PPR-1幼苗约为70％。