Genetic analysis of the yield and quality of peach cultivars and hybrids

Abstract

The following components have been detected as the elements of a genetic analysis of the yield and the chemical composition of the fruit (its total content of dry matter, soluble solids, total sugars, sucrose, reducing sugars and total acids): components of variability, variation coefficients, heritability coefficients in a wider sense of this term. Apart from the indicators listed here, a calculation has been made for the genetic and phonotypic correlations between the analyzed features. The interaction expressed by a formula: genotype (cultivar) x year had caused, in majority of cases, a variability in the total content of dry matter (S²gy = 48%), as well as in the content of soluble solids (S²gy = 72%), total sugars content (S²gy = 33%), reducing sugars content (S²gy = 45%) and contents of total acids (S²gy = 67%). The genetic difference between the peach cultivars and the hybrids were reflected in the variability of sucrose content (S²g = 58%), whereas the difference in the years when it was tested, caused the variability in the yield (S²y = 69%). A relatively high value of the heritability coefficient (83.7%) was recorded only in the total dry matter content, while for the other qualities relating to the chemical composition of the fruit and for yield, the heritability coefficient was ranged between the low and medium (21.0-63.5). The coefficients of genetic correlation between the yield on one side and the sucrose contents (rg = 0.831**), soluble solids contents (rg = 0.632*), total sugars content (rg = 0.578*) and organic acids contents (rg = -0.627*) on the other side, were significant. At the same time, the coefficients of the phenotypic correlation between the yield and the listed chemical characteristics of the fruit did not show any statistically significant values, which indicates that it is possible to perform parallel breeding, both for the yield and the quality of the fruit.

Kao elementi genetičke analize prinosa i kvaliteta ploda utvrđene su komponente varijabilnosti, koeficijenti varijacije i koeficijenti heritabilnosti u širem smislu. Pored navedenih pokazatelja izračunati su i koeficijenti genetičkih i fenotipskih korelacija između analiziranih osobina. Interakcija genotip (sorta) x godina u najvećem procentu uslovila je varijabilnost sadržaja ukupnih suvih materija (S2gy = 48%), sadržaja rastvorljivih suvih materija (S2gy = 72%), sadržaja ukupnih šećera (S2gy = 33%), sadržaja redukujućih šećera (S2gy = 45%) i sadržaja ukupnih kiselina (S2gy = 67%), genetičke razlike između sorti i hibrida breskve varijabilnost sadržaja saharoze (S2g = 58%), a razlike u godinama ispitivanja varijabilnosti prinosa (S2y = 69%). Relativno visoka vrednost koeficijenata heritabilnosti (83,7%) ustanovljena je samo za sadržaj ukupnih suvih materija, dok je za ostale osobine koje se odnose na hemijski sastav ploda i za prinos vrednost koeficijenata heritabilnosti bila slaba do srednja (21,0-63,5). Koeficijenti genetičke korelacije između prinosa s jedne strane i sadržaja saharoze (rg = 0,831**), sadržaja rastvorljivih suvih materija (rg = 0,632*), sadržaja ukupnih šećera (rg = 0,578*) i sadržaja organskih kiselina (rg = -0,627*) s druge strane su bili značajni, dok koeficijenti fenotipske korelacije između prinosa i navedenih hemijskih osobina ploda nisu pokazali statističku značajnost. To ukazuje da je moguće istovremeno vršiti selekciju i na prinos i na kvalitet ploda.