Genetic analysis of androgenetic competence and plants regenerated from callus culture of diploid potato species

Inheritance of androgenetic competence was studied in 10 diploid potato species hybrids and 16 backcross progeny. Ten hybrid families including three reciprocals were generated between competent clones of S. phureja and incompetent clones of S. berthaultii, S. microdontum and S. phureja. The F₁ hybrid families segregated for androgenetic competence with some highly competent and some incompetent genotypes in all families. The expression of androgenetic competence was modified by parents lacking competence. The cytoplasm of species lacking competence exerted a greater influence on the expression of androgenesis in intraspecific than in interspecific hybrids. The segregation data of 16 backcross progeny between a highly competent hybrid and its incompetent parent suggested that competence may be under control of a single dominant gene. Androgenetic competence can be transferred among sexually compatible potato species. The transfer of desirable traits to a monoploid background can be expected using an- drogenetically competent selections in hybrid combination with germplasm expressing the desired attributes. In an attempt to determine genetic changes of regenerated potato plants following anther and callus cultures, 20 callilines of two S. phureja clones were examined. Four of 20 callilines selected for fertility and diploidy were morphologically indistinguishable among themselves and from the parental clone that had not undergone a tissue culture cycle. Even though morphologically indistinct from the parental clone, all four callilines exhibited higher seed set as pollen parents in 4x-2x crosses and two of the four exhibited higher recombination frequency between the centromere and the y gene. The estimated increase in map distance of the y locus ranged from 3.4 to 10.0 units. Progeny analysis revealed no significant morphological differences among 4x-2x hybrid families under field conditions, and only a single difference among 2x-2x hybrid families under screenhouse conditions. Hence, variation induced in tissue culture may have occurred without detectable morphological change. Assuming no adverse tissue culture effects, breakage of undesirable linkage groups may be an advantage of caulogenesis before backcrossing.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Genetics

Department dc:contributor.department

Genetics

Grantor dc:publisher

Virginia Polytechnic Institute and State University

Year dc:date.issued

1988

Author dc:creator

• Singsit, Chongkhohao

Chair dc:contributor.committeechair

• Veilleux, Richard E.

Committee members dc:contributor.committeemember

• Buss, Glenn R.
• Esen, Asim
• Radin, David N.
• VanScoyoc, Stephen W.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/77839

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/77839