|Nualsri, Charassri - PR SONKHLA UNIV THAILAND|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 23, 1998
Publication Date: N/A
Interpretive Summary: Lotus corniculatus L. (broadleafed birdsfoot trefoil) is a forage legume grown in the United States, Canada, South America and Europe. Long-lived and productive stands of L. corniculatus depend on natural reseeding and individual plant persistence. Wild plants of L. corniculatus from Morocco are unique in that they produce rhizomes (stems that spread underground) which may prove useful in increasing the longevity of our cultivated varieties. The objective of this study was to determine how rhizomes are inherited in L. corniculatus. To study the inheritance of rhizomes we developed self-pollinating hybrids and their offspring to use as research tools. Our observations from other studies suggested that rhizomes were inherited as a dominant trait and this research confirmed our observations. Our examination of the hybrids and their offspring indicates that rhizome presence is controlled by a single dominant gene and conforms to simple Mendelian genetics principles. We propose to name the gene for rhizomes in L. corniculatus and identify it by the symbol R. The findings of this research will result in the faster development of new L. corniculatus cultivars with rhizomes, and may lead to the isolation of the rhizome gene. Once the gene is isolated, it can be transferred to different species of plants that could benefit from rhizomes.
Technical Abstract: Introduction of rhizomes from wild Lotus corniculatus L. (broadleafed birdsfoot trefoil) germplasm from Morocco is considered an important step towards improving persistence of cultivated L. corniculatus, a cross-pollinated herbage crop. Rhizome-production has been successfully transferred from wild germplasm of broadleafed birdsfoot trefoil into domesticated cultivars and autogamous germplasm. The objective of this study was to determine the inheritance of rhizomes in L. corniculatus. Crosses were made between AG-S4, an autogamous, non-rhizomatous germplasm and two rhizomatous accessions from Morocco, G31276 and G31317. Two autogamous progeny from each cross (verified as F1 hybrids by morphological and random amplified polymorphic DNA markers) produced F2 seed and were reciprocally backcrossed (BC). After 10 mo growth in the greenhouse, F2 and BC progeny were scored for rhizome production. Plants failing to express rhizomes in greenhouse conditions were transplanted to the field and reevaluated for presence or absence of rhizomes at the end of the growing season. Segregation ratios for rhizome expression were tested for goodness-of-fit by the Chi-square test. The ratios of rhizome production in F2 and BC's to AG-S4 fit 3:1 and 1:1 dominant:recessive ratios indicating that rhizome presence in L. corniculatus is controlled by a single dominant gene. The gene symbol R is proposed for rhizome expression.