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Estimation of genetic gain, productivity and phenotypic stability of poplar clones in the area of eastern Croatia

Davorin Kajba orcid.org/0000-0001-9194-1030 ; Šumarski fakultet Sveučilišta u Zagrebu
Ivan Andrić ; Šumarski fakultet Sveučilišta u Zagrebu

Sažetak

Research into phenotypic stability, adaptability and productivity of poplar clones at younger plantation was conducted in the lower course of the River Drava and the tributary of the River Danube in the eastern Croatia. In this area, the construction of river infrastructure has led to severe changes in the water regime. It is for this reason that the selected poplar clones should be adapted to the specific new condition of low groundwater levels. The assessment of genetic parameters, productivity and phenotypic stability for 14 poplar clones at plantation age of 2+5 years were evaluated in five clonal trials in the area of Eastern Croatia. The tests were set up at planting distances of 6 × 6 m randomized with 16 plants per block and four repetitions. At the moment of experimental plot establishment, the planting material was 1/2 and 2/3 years old. Statistically significant interclonal variability in production and survival was found in particular clonal tests. Mean survival in the clonal test established with plants aged 1/2 years was 72 % on average, whereas it was 95 % in the test with plants aged 2/3 years, which suggests that using of planting material at age 2/3 years is much more successful. Research on adaptability and genotype × environment interaction were conducted for the same eight poplar clones in three trials. From a silvicultural standpoint, the most suitable clones for generating optimal modifications, as a rule, were those of high phenotypic instability. Their cultivation is justified on optimal sites, as well as on less favourable sites when are provided agrotechnical measures and applied adequate protection measures. Based on the size of regression coefficients and regression analysis, it can be concluded that the tested clones can be divided, in terms of phenotypic stability and productivity, into three groups: a) phenotypically stable clones of medium productivity and a tendency to adapt to all environments (´I-214´, ´M 1´, ´S 6-36´, ´S 6-20´; b) moderately stable clones, of moderate productivity which manifest a tendency to adapt to all environments (‘710’, ´Bl Constanzo´, ´Pannonia´); and c) phenotypically very instable clones of high production capacity, with specific adaptation to optimal sites (´S 1-8´). Levels of the genetic control for the growing stock, heritability values (h2) and genetic gain (∆G) were assessed on the basis of selecting five or one of the best clones. The expected genetic gain was compared with the obtained experimental data. Assessment of the heritability values (h2) ranged from 0.40 to 0.90, which indicates that the traits of production and adaptability is under a high degree of genetic control. The obtained genetic gain (∆G) in growing stock production for the best five selected clones was somewhat higher than expected and ranged from 15.30 to 45.12 %, whereas it was between 30.88 and 81.03 % for one best selected clone. In order to minimize the risk of cultivating one clone (monoclonal culture) and increase plantations stability, we will favour the cultivation of a mixture of five clones of divergent genetic constitution. The results of this research confirm that even at such a young plantation age the quality of a particular habitat has conditioned modifications in average clone values of growing stock and survival. They also indicate the amount of production to be expected from the mixture of these clones or from the cultivation of a particular clone.

Ključne riječi

adaptability; genetic parameters; genotype × environment interaction; poplar clones

Hrčak ID:

84708

URI

https://hrcak.srce.hr/84708

Datum izdavanja:

30.6.2012.

Podaci na drugim jezicima: hrvatski

Posjeta: 1.898 *