TY - CONF
T1 - Drought tolerance of interspecific hybrids between T. repens and T. ambiguum
AU - Marshall, Athole H.
AU - Abberton, Michael T.
AU - Michaelson-Yeates, Terry P. T.
AU - Rhodes, Ian
AU - Williams, T. Andy
N1 - Marshall, A. H., Abberton, M. T., Michaelson-Yeates, T. P. T., Rhodes, I., Williams, T. A. (2001). Drought tolerance of interspecific hybrids between T. repens and T. ambiguum. Grassland Ecosystems: An Outlook into the 21st Century. Proceedings 19th International Grassland Congress, Sao Paulo, Brazil, 10-21 February 2001, Gomide, J. A.Mattos, W. R. S.Carneiro da Silva, S. Fundacao Estudos Agrarios Luiz Queiroz (Fealq), Piracicaba, 528-529
Gomide, J. A.; Mattos, W. R. S.; Carneiro da Silva, S. (eds.)
PY - 2001
Y1 - 2001
N2 - Hybrids between the stolonifeous white clover (Trifolium repens L., 2n=4x=32) and
rhizomatous Caucasian clover (T. ambiguum M.Bieb, 2n=4x=32) have been produced. A
backcross 2 (BC2) generation with white clover as the recurrent parent combines the growth
habit of both parent species with the objective of increasing the persistency of large leaved T.
repens varieties under grazing. T. ambiguum is more drought tolerant than T. repens. The
drought tolerance of the hybrids in comparison with the parental species was compared in
deep soil bins over a four week drought cycle. Soil moisture content, leaf relative water
content (RWC), and leaf water potential were measured on plants subjected to drought and
those watered normally and maintained at field capacity. T. ambiguum and the backcross
hybrids were able to maintain a higher leaf RWC and leaf water potential than T. repens at
comparable levels of soil moisture. The dry matter production of the hybrids and parental
species was also compared in field plots sown with a perennial ryegrass companion. In the
first harvest year, under a cutting regime, the yield of T. repens was highest and T. ambiguum
lowest with the hybrids intermediate between the parents, with the BC2 approaching the yield
of T. repens. These hybrids will be evaluated over further years and under grazing. The implications of these results for T. repens germplasm improvement programmes are
discussed.
AB - Hybrids between the stolonifeous white clover (Trifolium repens L., 2n=4x=32) and
rhizomatous Caucasian clover (T. ambiguum M.Bieb, 2n=4x=32) have been produced. A
backcross 2 (BC2) generation with white clover as the recurrent parent combines the growth
habit of both parent species with the objective of increasing the persistency of large leaved T.
repens varieties under grazing. T. ambiguum is more drought tolerant than T. repens. The
drought tolerance of the hybrids in comparison with the parental species was compared in
deep soil bins over a four week drought cycle. Soil moisture content, leaf relative water
content (RWC), and leaf water potential were measured on plants subjected to drought and
those watered normally and maintained at field capacity. T. ambiguum and the backcross
hybrids were able to maintain a higher leaf RWC and leaf water potential than T. repens at
comparable levels of soil moisture. The dry matter production of the hybrids and parental
species was also compared in field plots sown with a perennial ryegrass companion. In the
first harvest year, under a cutting regime, the yield of T. repens was highest and T. ambiguum
lowest with the hybrids intermediate between the parents, with the BC2 approaching the yield
of T. repens. These hybrids will be evaluated over further years and under grazing. The implications of these results for T. repens germplasm improvement programmes are
discussed.
M3 - Paper
SP - 10
EP - 21
ER -