ARS | Publication request: DEPENDENCE ON EXOGENOUS GIBBERELLIN FOR SEED GERMINATION IN SOLANUM ACAULE AND OTHER SOLANUM (POTATO) SPECIES

Submitted to: American Journal of Potato Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 19, 1999
Publication Date: N/A

Interpretive Summary: Maximum germination of potato seeds is needed in various potato germplasm, breeding and crop production endeavors. Gibberellin (GA) is a common plant hormone known to enhance final percent germination of potato seeds when exogenously applied, expecially when seed are newly harvested and naturally dormant. Routine germination tests identified populations of aged seed within a single potato species with exteme differences in response to soaking in 2,000 ppm GA. In other words, some populations' seeds would not germinate at all without the artificial application of GA, while others had total germination when untreated with GA. The trait bred true within types, and intermediate germination occured in hybrids between types. A broad survey of over 2,500 populations in the US Potato Genebank revealed other populations with a high dependence on GA for germination. This discovery has practical applications, which may include facilitating accurate seed germination tests for genebanks and providing a tool for further study of the dynamics of GA seed physiology both of populations kept in the genebank and those existing naturally in the wild.

Technical Abstract: Certain seed populations of the wild potato species Solanum acaule were identified as having consistent qualitative dependence on GA to germinate. This was true for both germination in petri plates and in greenhouse conditions. The effect could be transmitted across sexual generations. Crosses with GA-independent populations were intermediate, with no clear reciprocal effect. A broad survey of 2,580 populations including 60 potato species indicated that significant dependence on GA also exists in other species. This trait may have physiological and evolutionary implications worth further investigation. Recognizing that populations of some species are highly dependant on GA allows genebank managers and other potato scientists to accurately assess seed viability and avoid inadvertent selection against useful traits which may be linked.