Author
GLENN, DAVID | |
GASIC, KSENIJA - CLEMSON UNIVERSITY |
Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/14/2015 Publication Date: 7/29/2015 Citation: Glenn, D.M., Gasic, K. 2015. Influence of within year treatments and between year environmental differences on peach leaf ash and carbon isotopic discrimination responses. Scientia Horticulturae. 193:258-260. Interpretive Summary: In breeding programs, the genetic vs environment interaction for ash or isotope discrimination related to water use efficiency has not been studied. Researchers studied how within yearly cultural variation vs yearly environmental variation affect peach leaf ash and carbon discrimination as measures of water use efficiency using cultural practices for a 13 year period of time. ‘Loring’ peach were planted in square vegetation-free-areas (VFA) around each tree and 3 irrigation treatments were imposed on each VFA. Leaf ash and carbon isotope discrimination (Delta 13C) were measured in leaf tissue collected prior to harvest. There were no differences in VFA or irrigation for either ash or Delta 13C. However, there were yearly interactions. Delta 13C was significantly related to the growing season pan evaporation and leaf ash was significantly related to the growing season rainfall amount. These data suggest breeding program screening for increased water use efficiency with leaf ash or Delta 13C can anticipate a minimal amount of within location variation and thus, place more emphasis on environmental or between-location variation. Technical Abstract: Plant ash content is related to water use efficiency (WUE) (dry matter accumulation per unit of transpiration) and Delta 13C in a range of C3 species. In breeding programs, the genetic x environment interaction is measured with multiple locations and multiple years of evaluation but the genetic x environment interaction of ash or Delta 13C has not been studied. The purpose of this study was to assess how within year cultural variation and yearly environmental variation affect peach leaf ash and carbon discrimination as measures of water use efficiency using cultural practices evaluated over a 13 year period of time. ‘Loring’ peach (Prunus persica) on seedling ‘Halford’ rootstock were planted in 1983 in a 4.5m x 6m spacing in square vegetation-free-areas (VFA) around each tree (0.36 and 13.0 m squared). Three irrigation treatments (none, drip irrigated during stage 3 of fruit development, and fertigation during stage 3 of fruit development) were imposed on each VFA. Leaf ash and carbon isotope discrimination (Delta) were measured in leaf tissue collected prior to harvest. Analysis of variance indicated that there were no differences in VFA or irrigation for either ash or Delta 13C, however, there were yearly interactions. Delta 13C was significantly related to the growing season pan evaporation but the slope was low indicating a minimal response while leaf ash was not significantly related. In contrast, leaf ash was significantly related to the growing season rainfall amount while Delta 13C was unrelated. Both leaf ash and Delta 13C were unrelated to the growing season water deficit. The coefficient of variation for leaf ash and Delta 13C are 0.16 and 0.04, respectively, over a 13 year sampling period. These data suggest that breeding programs screening for increased water use efficiency using leaf ash or Delta 13C can anticipate a minimal amount of within location variation and thus place more emphasis on environmental or between-location variation. |