Seed set efficiency of sunflower genotypes in different ecological conditions

Abstract

Analysis of seed set efficiency of sunflower genotypes in different ecological conditions was carried out at Rimski šančevi experimental field. Testing was conducted during a tree year period on 30 genotypes developed at the Institute of Field and Vegetable Crops, Novi Sad. Nectar production, visitation of pollinators, pollen viability, self-fertility and seed set efficiency were analyzed. Association between the seed set efficiency and other traits was examined using multivariate analysis. The existance of highly significant differences between genotypes was observed for all of the traits analyzed. Highly significant differences were obtained for nectar production, bumble bee visitation and pollen viability beetwen the years, whille for total visitation of pollinators, significant differences were recorded. These results indicate high effect of environmental factors on development of these traits. No significant differences between the years were recorded for bee visitation, self-fertility and seed set efficiency, indicating higher effect of genotype in development of these traits. Multivariate analysis showed positive association between seed set efficiency and pollen viability. Association between seed set efficiency and nectar production varied from strong positive to strong negative. During the study, visitation of pollinators was in weak association with seed set efficiency. Bumble bee visitation had stronger association with seed set efficiency than total visitation and bee visitation. Association between self-fertility and seed set efficiency varied from weak to negative. Additionally, associations among the seed set efficiency, yield and yield contributing traits were analyzed. Seed set efficiency showed positive association with seed yield, oil yield, head diameter and 1000 seed weight. Oil content and number of flowers per head were negatively associated with seed set efficiency. Results obtained in this study will contribute in better understanding of seed set efficiency in sunflower and factors that affect it.

Eksperiment za ispitivanje efikasnosti oplodnje genotipova suncokreta u različitim ekološkim uslovima postavljen je na oglednom polju Rimski šančevi. Ispitivanje je vršeno tokom tri godine na 30 različitih genotipova stvorenih na Institutu za ratarstvo i povrtarstvo, Novi Sad. Analizirana je produkcija nektara, poseta oprašivača, vitalnost polena, autofertilnost i efiksanost oplodnje. Primenom multivarijacione analize, ispitana je veza između efikasnosti oplodnje cvasti i ostalih osobina. Kod svih ispitivanih osobina uočeno je postojanje visoko značajnih razlika između genotipova. Visoko značajne razlike između godina zabeležene su kod produkcije nektara, posete bumbara i vitalnosti polena, dok je kod ukupne posete oprašivača utvrđena značajna razlika. To ukazuje na značajan uticaj klimatskih faktora na ove osobine. Kod posete pčela, stepena autofertilnosti i efikasnosti oplodnje nisu uočene značajne razlike između godina, što ukazuje na veći značaj genotipa u ispoljavanju ovih osobina. Multivarijacionom analizom pokazana je pozitivna veza između efikasnosti oplodnje i vitalnosti polena. Asocijacija između oplodnje i produkcije nektara je tokom godina varirala od jake pozitivne do jake negativne. Poseta oprašivača je tokom istraživanja bila u slaboj asocijaciji sa oplodnjom. Iz posete oprašivača izdvaja se poseta bumbara, koja je bila bliže vezana sa oplodnjom nego ukupna poseta oprašivača i poseta pčela. Asocijacija između autofertilnosti i efikasnosti oplodnje cvasti varirala je od slabe do negativne. Dodatno, ispitana je veza efikasnosti oplodnje sa prinosom i osobinama značajnim za njegovo formiranje. Efikasnost oplodnje je tokom godina bila u pozitvnoj vezi sa prinosom semena, prinosom ulja, prečnikom glavice i masom 1000 semena. Sadržaj ulja i ukupan broj cvetova su bili u negativnoj vezi sa oplodnjom. Dobijeni rezultati doprinose boljem razumevanju efikasnosti oplodnje suncokreta i faktora koji na nju utiču.