Comparison of interconnections between barley breeding material traits under organic and conventional growing conditions Legzdina, 1A. Kokare , 1I.Beinarovica and 2E.T. Lammerts van Bueren 1L. 1 State Priekuli Plant Breeding Institute, Latvia firstname.lastname@example.org 2Wageningen UR Plantbreeding, Wageningen University, The Netherlands Introduction While breeding for organic farming it is necessary to identify the most appropriate growing conditions in which to perform the selection process. Soil fertility, crop management, yield level and other factors may vary very much between each organic farm, and between organic farms and research institutions where the selection is usually performed. Since plant breeding requires considerable input of resources and the market for organic varieties is limited, it is essential to find the most appropriate selection conditions that will provide acceptable varieties for organic farms. Defining the most suitable selection environments was pointed out among the key questions for development of breeding strategies for organic farming (Wolfe et al., 2008). The aim of this study was to find out if there are different tendencies in correlations between the traits under different organic and conventional conditions. Material and methods Spring barley breeding lines selected from two cross combinations (Primus/Idumeja and Anni/Dziugiai) at two distinctive organic and two conventional locations (Table 1) were used in the study. ‘Primus’ is late maturing, old Swedish variety with very tall plants. It was crossed with recently released, early maturing Latvian variety ‘Idumeja’ with medium tall plants. In the second cross the short straw Estonian variety ‘Anni’ (developed in 1990-ties) with good yields under various growing conditions was crossed with the Lithuanian variety ‘Dziugiai’ from the middle of last century, with quite tall plants, poor lodging resistance, but with a rapid early development. Selection of the breeding lines was done under the respective growing conditions starting from F3 generation. Most appropriate lines for growing in organic farming were selected at all 4 environments. Selected breeding lines were evaluated for traits essential for organic farming in F5 and F6 generations and in F7 comparison of selected lines was done in all four Figure 1. Scheme of the breeding experiment, Priekuli 2006-2010. environments (fig. 1). Phenotypic correlations between barley traits were calculated. Table1. Description of crop management systems at two organic and two conventional trial locations in Priekuli, 2006 – 2010. Soil shading ability Plant development speed C2 * C2 Fertility management Management of Primus/Idumeja Anni/Dziugiai Anni/Dziugiai ** C1 C1 Location Pre-crop Diseases, O2 ** ** Amount of N Type (amount) pests Weeds O2 ** -1 O1 ** O1 Organic 1 Green manure N 26.5 kg ha Rapeseed or peas for No harrowing 2010 -1 (O1) crop green manure (~20 t ha ) 2009 Primus/Idumeja C2 C2 * organic trial field C1 C1 ** 2008 -1 ** ** Organic 2 Perennial N 41 kg ha Stable manure (cows) (~40 No No -1 O2 ** ** O2 ** ** (O2) grasses or t ha ) ** ** * organic farm cereals O1 ** O1 ** -1 Conventional 1 (C1) Potatoes N 80 kg ha Inorganic Insecticide Herbicide -0.2 0 0.2 0.4 0.6 0.8 1 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 breeding field if needed Plant height in beginning of stem elongation -1 Plant height before harvest Conventional 2 (C2) Potatoes 120 kg ha Inorganic Insecticide Herbicide ** C2 Seed production if needed C2 Anni/Dziugiai Anni/Dziugiai field C1 ** C1 ** O2 O2 ** Results * O1 O1 The analysis of the correlation between grain yield and observed plant traits indicated that tendencies for the lines obtained from both cross combinations as well as between the locations and testing years Primus/Idumeja Primus/Idumeja C2 C2 ** ** ** were dissimilar in most of the cases. C1 C1 ** Soil shading correlated positively with grain yield in most of the cases (fig.2), but the correlation was O2 ** O2 significant in all years only for lines selected from cross Primus/Idumeja in O1 location. On the whole O1 ** O1 ** ** higher correlation coefficients were found for Primus/Idumeja lines and in organic locations, which can be ** explained by higher competitive ability with weeds. -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 Plant development speed (scored in tillering) correlated with yield significantly positive for TGW Protein Primus/Idumeja lines in most of the cases in both organic and also C1 locations. For lines selected from ** C2 ** * C2 cross Anni/Dziugiai this correlation was positive only in O2 location, but also negative tendencies were Anni/Dziugiai Anni/Dziugiai ** ** C1 found. C1 On the whole, higher positive correlations between plant height (measured in stem elongation and before O2 O2 harvest) and yield were stated in organic locations and for lines derived from cross Primus/Idumeja. Plant O1 ** O1 height in stem elongation for Anni/Dziugiai lines in 2010 correlated significantly positive in O2 location, ** ** C2 however, in the same year it was significantly negative in C2 location. Primus/Idumeja C2 Primus/Idumeja ** C1 C1 Unusual tendencies were found for correlations between grain protein content and yield under organic O2 ** O2 conditions: for Anni/Dziugiai lines there were no negative correlations (2009-2010) and for Primus/Idumeja O1 ** O1 ** lines the correlation was even significantly positive in 2010. On the contrary, correlation coefficients between yield and grain starch content were positive and on the whole higher in conventional locations. -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 TGW correlated positively with yield in 2010 only and in all locations except O2. Figure 2. Coefficients of correlation between grain yield and traits of lines selected from two cross combinations in two organic and two conventional locations in the years 2008-2010 (*, ** significant at the 0.05 and 0.01 level, respectively). Soil shading correlated positively with leaf position and plant development speed in majority of the cases in organic and in conventional locations (data not shown). Regarding plant height, significant Soil shading / plant growth habit positive correlations with soil shading were found in more cases if it was measured in stem elongation if compared to measurement in maturity. C2 Anni/Dziugiai The results of this study does not approve the usefulness of leaf length and width measurements for ** C1 selection purposes: no significant positive correlations with soil shading ability were found for both * O2 measurements under organic conditions. However, in two cases leaf length correlated positively with grain O1 2010 yield. ** Correlations between soil shading and lodging were mostly negative indicating that genotypes with better 2009 Primus/Idumeja C2 soil shading ability are less resistant to lodging. This fact might cause a problem under organic conditions 2008 C1 with higher fertilization level. O2 Dissimilar tendencies in correlations between soil shading and plant growth habit for lines from both cross combinations are shown in Figure 3. For Anni/Dziugiai lines most of correlations are negative indicating O1 that soil shading was better for lines with erect growth habit, while for other cross combination lines with -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 more planophyle growth habit provided better shading. It can be explained by strong and significantly Figure 3. Coefficients of correlation between soil shading and plant growth habit negative correlation between planophyle growth habit and plant development speed which was found for of lines selected from two cross combinations in two organic and two conventional Anni/Dziugiai lines in majority of the cases. locations in the years 2008-2010 (*, ** significant at the 0.05 and 0.01 level, respectively). Conclusions •In the selection process it has to be considered, that the tendencies of correlative connections may differ between the cross combinations. Differences between the years suggest that meteorological conditions can influence correlative connections between the traits. •Positive correlations between grain yield and soil shading ability gives a possibility to select lines with good yield and good competitive ability with weeds at the same time; higher correlation coefficients under organic conditions approve the positive effect of better ability to compete with weeds. •Plant development speed can be positively related with grain yield, especially under organic and lower input conditions, but not under high input conventional conditions. •The interconnection between grain yield and protein content might be not negative under organic conditions in contrary to conventional conditions. •Essential traits for assessment of competitive ability with weeds according to correlations with soil shading are plant development speed, leaf position and plant height in beginning of stem elongation stage. Reference Wolfe MS, Baresel JP, Desclaux D, Goldringer I, Hoad S, Kovacs G, Löschenberger Acknowledgements F, Miedaner T, Østergård H, Lammerts van Bueren ET (2008) Developments in This study was performed with financial support of EEA grant EEZ08AP-27 and European breeding cereals for organic agriculture. Euphytica, 163: 323-346. Social Fund co-financed project 2009/0218/1DP/18.104.22.168.0/09/APIA/VIAA/099.
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