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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 #306772

Title: Field performance of vegetative form traits of neopolyploids produced by in vitro colchicine treatment in Pyrus communis

Author
item SUN, QINGRONG - Shandong Institute
item SUN, HONGYAN - Shandong Institute
item Bell, Richard
item LI, LINGUANG - Shandong Institute
item ZHOU, GUANGFANG - Shandong Institute
item XIN, LI - Shandong Institute

Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/26/2015
Publication Date: 6/30/2015
Citation: Sun, Q., Sun, H., Bell, R.L., Li, L., Zhou, G., Xin, L. 2015. Field performance of vegetative form traits of neopolyploids produced by in vitro colchicine treatment in Pyrus communis. Scientia Horticulturae. DOI: 10.1016/j.scientia.2015.06.047.

Interpretive Summary: Polyploids, that is plants with more than the normal (diploid) two sets of chromosomes, often show novel traits that are not present in their diploid progenitors. These traits include more compact growth habit, increased resistance to drought, pest resistance, and fruit size that could be useful for fruit production as fruit-bearing cultivars or rootstocks. Six neopolyploids of the pear cultivar ‘Fertility’ that had been obtained by treatment of pear shoot cultures with the chemical colchicine were compared to their normal progenitor clone in greenhouse and field studies for changes in vegetative traits. All polyploids showed reductions in plant height, trunk diameter, current season shoot length and internode length. Petiole lengths were shorter, leaf width was greater. The direction and significance of differences in petiole width and leaf thickness depended on the specific polyploidy clone, independent of the number of chromosome set. The diversity of neopolyploid variation could be used to develop improved pear cultivars and rootstocks.

Technical Abstract: The induction of polyploidy to improve agronomically and economically useful characters is a process commonly used in crop plants. Neopolyploids were obtained from pear diploid cultivar ‘Fertility’ by in vitro colchicine treatment. Different ploidy clones were rooted to be transferred to the field and established a survey orchard. The morphological characteristics and the performance of 3 tetraploid clones, 2 triploid clones, 1 mixploid clone and diploid control were investigated under greenhouse and field conditions. Results showed that plants of different neopolyploids showed markedly different phenotypic traits. Compared to the diploid control, all polyploid plants had significantly larger leaf thickness and smaller petiole length. The significance of difference in leaf index (ratio of leaf lamina length to leaf lamina width) between diploid and polyploids depended on different ploidy plants. Triploid clone ‘3x-1’ and tetraploid clones ‘4x-1’ and ‘4x-2’ had significantly decreased leaf index, and triploid ‘3x-2’ had significantly increased leaf index. However, tetraploid clone ‘4x-4’ and mixploid clone ‘Mix-1’ showed phenotypic abnormality, such as stunted growth and leaf malformation. The ex vivo grafted shoots of pentaploid ‘5x-1’ and ‘5x-2’ were very difficult to survive or very short survival. The grafted plants of triploid ‘3x-2’ showed compact habit. All neopolyploid plants had significantly shorter internodes and reduced plant height than that of their parent diploid plants.