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ARS Home » Northeast Area » Kearneysville, West Virginia » Appalachian Fruit Research Laboratory » Innovative Fruit Production, Improvement, and Protection » Research » Publications at this Location » Publication #311901

Title: Comparative organogenic responses of six clonal apple rootstock cultivars

Author
item SUN, QINGRONG - Shandong Institute
item SUN, HONGYAN - Shandong Institute
item Bell, Richard
item LI, LINGUNG - Shandong Institute
item TAO, JIHAN - Shandong Institute
item ZHOU, GUANGFANG - Shandong Institute
item XIN, LI - Shandong Institute

Submitted to: HortScience
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/28/2015
Publication Date: 3/1/2016
Citation: Sun, Q., Sun, H., Bell, R.L., Li, L., Tao, J., Zhou, G., Xin, L. 2016. Comparative organogenic responses of six clonal apple rootstock cultivars. HortScience. 51(3):272-278.

Interpretive Summary: The ability to induce the formation of new plants from cells from mature leaf tissue, a process called organogenesis, is a necessary step for genetic engineering of improved crop plants. The organogenesis potential of different plant varieties can vary, and the artificial culture medium must be optimized for individual varieties. The purpose of the study was to determine the optimum culture medium components for six new apple rootstock varieties for shoot and root formation. Two artificial culture media differing in the concentrations of various mineral nutrients, the type of a class of hormones called cytokinins, and their concentration were examined to select the best culture media for shoot and root organogenesis for each variety. The effects of culture medium composition and cytokinins on shoot regeneration were different depending on rootstock. The percentage of rooting reached more than 90 percent and the mean root number per plantlet ranged from three to five. The optimum rooting medium differed, depending on the rootstock. Optimum root organogenesis occurred on half-strength QL medium for ‘GM256’ and ‘Y’, and on one-quarter-strength MS medium for ‘PB’ and ‘JM7’. Scientists working on genetic engineering of these apple rootstocks can select the optimum growth media identified by this research when seeking to improve the varieties for specific traits.

Technical Abstract: The organogenesis potential is different among cultivars and must be optimized for individual genotypes. Shoot organogenesis capacity from leaf explants and root organogenesis capacity of in vitro shoots in six clonal apple rootstock cultivars were compared. The shoot organogenesis capacity was highly genotype-dependent. ‘GM256’ was found to be the most responsive genotype for shoot regeneration from leaf explants among the cultivars, showing high regeneration percentage on all tested media. The effects of basal medium composition and cytokinins on shoot regeneration were different depending on rootstock genotype. Optimum regeneration occurred on MS basal medium for ‘71-3-150’, and optimum regeneration occurred on QL basal medium for ‘60-160’ and ‘PB’. Thidiazuron (TDZ) was more effective than 6-benzylaminopurine (BA) for Malus prunifolia (Y), while TDZ and BA were not significantly different for the other cultivars. All rootstock cultivars showed high root organogenesis capacity. The percentage of rooting reached more than 90 percent and the mean root number per plantlet ranged from three to five. The optimum rooting medium was different for different rootstock cultivars. Optimum root organogenesis occurred on half-strength Quoirin and Lepoivre medium for ‘GM256’ and ‘Y’, and on one-quarter-strength MS medium for ‘PB’ and ‘JM7’.