Effect of water deficit stress on 11 native Fragaria chiloensis clones selected as ornamental groundcovers

Eleven Fragaria chiloensis (L.) Duch. genotypes were used in a comparative study to evaluate predawn water potential (psi) and physiological recovery after an imposed water deficit stress. Originally collected from sites along the California and Oregon coasts, these clones had previously been screened for their potential as ornamental groundcovers. Initial predawn psi were similar across controls (well watered) and treatments. At the completion of the first 12 day water deficit stress cycle, clones I05, STR, Q18 and DNT had psi of -1.2 MPa, -0.87 MPa, -0.87 MPa and -0.65 MPa, respectively, significantly higher than clones T03, S19 and O15 with psi of -3.5 MPa, -3.5 MPa and -3.1 MPa, respectively, When the second 12 day water deficit stress cycle was complete, all treatment clones except DNT and STR were significantly more stressed than control clones. There were no differences among clones within the treatment group. Predawn psi was strongly correlated with assimilation on a leaf area basis (A(LA)) after the first (r = 0.87) and second (r = 0.83) water deficit stress cycles. After the first 40 day recovery period there were no differences among clones in the treatment group in total number of runners, daughter plant number or runner length. However, differences were observed in all three parameters among clones in the control group. At the completion of the second 40 day recovery period, treatment clone 105 produced significantly more runners than clones STR, Q18, TOT and FV and more daughter plants than clones Q18, TOT and FV. Clone O15 produced longer runners than Q18, TOT and FV. Genotypic differences in runner number, daughter plant number and runner length were again seen in the control group. This study demonstrated differences in both predawn psi and above ground biomass production of 11 F. chiloensis clones after two imposed water deficit stress/recovery cycles as well as a strong relationship between predawn psi and A(LA).