Grain-to-spike weight ratio in different wheat genotypes grown on humogley soil

Abstract

U ovom istraživanju analizirana je varijabilnost žetvenog indeksa klasa tj. odnosa mase zrna po klasu i ukupne mase klasa kod 16 divergentnih genotipova hlebne pšenice (Triticum aestivum var. vulgare) tokom dve vegetacione sezone (2015/2016 i 2016/2017). Odnos ove dve komponente prinosa predstavlja važan indikator efikasnosti preraspodele biomase u korist zrna, zbog čega ima veliki značaj u selekciji genotipova pšenice. Ogled je postavljen po slučajnom blok sistemu u tri ponavljanja na zemljištu tipa ritska crnica u Novom Bečeju (Vojvodina, Srbija). U sezoni sa povoljnom količinom i raspodelom padavina (2015/2016), najveću vrednost odnosa mase zrna i mase klasa je ispoljio genotip Fundulea 4 (0,83), zatim NS 58-04 i Tamiš (0,81), dok je genotip Iskra imao najnižu vrednost ovog parametra (0,74). U uslovima nedovoljne količine padavina, koji su karakterisali 2016/2017 sezonu, najveću vrednost odnosa mase zrna i mase klasa imao je genotip Dunavka (0,82), dok je najmanju vrednost imao genotip Kavkaz (0,64). Prosečna vrednost odnosa mase zrna i mase klasa za sve genotipove bila je značajno veća u povoljnoj sezoni (0,78) u odnosu na vrednost u uslovima suše (0,73). Dobijeni rezultati ukazuju na postojanje značajnih genotipskih razlika, što je potvrđeno primenom hijerarhijske klaster analize, sprovedene po Wardovom metodu, uz korišćenje Euklidove distance kao mere sličnosti između genotipova. U povoljnoj sezoni, klaster sa najvećom prosečnom vrednosšću odnosa mase zrna i mase klasa (0,81) čine genotipovi Fundulea 4, Poljana, NS 58-04 i Tamiš, što ukazuje na njihovu potencijalnu prednost u optimalnim uslovima gajenja. U sušnoj sezoni, genotipovi Dukat, Pitoma, Iskra, Poljana, Mačvanka i Vali PKA-7114 su grupisani unutar istog klastera, sa prosečnom vrednošću ispitivanog parametra od 0,77, što može ukazivati na njihovu bolju prilagodljivost u stresnim uslovima sredine.In this study, the variability of harvest index of spike i.e. grain-to-spike weight ratio was analyzed in 16 divergent bread wheat genotypes (Triticum aestivum var. vulgare) during two growing seasons (2015/2016 and 2016/2017). The ratio of grain weight per spike and spike weight represents an important indicator of biomass allocation efficiency towards grain, making it a valuable trait in the selection of wheat genotypes. The experiment was conducted using a randomized block design with three replications on humogley soil type, at the Novi Bečej locality (Vojvodina, Serbia). In the season with favorable amount and distribution of precipitation (2015/2016), the highest value of grain-to-spike weight ratio was exhibited in the genotype Fundulea 4 (0.83), followed by NS 58-04 and Tamiš (0.81), while the genotype Iskra had the lowest value of this parameter (0.74). Under conditions of insufficient precipitation, which characterized the 2016/2017 season, the highest value of the ratio of grain weight to spike weight was found in the genotype Dunavka (0.82), while the lowest value was observed in the genotype Kavkaz (0.64). The average value of the grain-to-spike weight ratio for all genotypes was significantly higher in the favorable season (0.78) compared to the value under drought conditions (0.73). The obtained results indicate the existence of significant genotypic differences, which was confirmed by hierarchical cluster analysis performed using Ward’s method, with Euclidean distance as a measure of similarity between genotypes. In the favorable season, the cluster with the highest average value of the grain-to-spike weight ratio (0.81) included the genotypes Fundulea 4, Poljana, NS 58-04, and Tamiš, indicating their potential advantage under optimal growing conditions. In the drought season, the genotypes Dukat, Pitoma, Iskra, Poljana, Mačvanka, and Vali PKA-7114 were grouped within the same cluster, with an average value of the examined parameter of 0.77, which may indicate their better adaptability to stressful environmental conditions