Estimation of diversity and combining abilities in Helianthus annuus L. under water stress and normal conditions

Abstract

ABSTRACT. Sunflower cannot produce high yields under waterlimiting conditions. The aim of the present study was to prevent the impediments on yield and to develop varieties with high-yield potential under water scarce conditions. For achieving this objective, it is necessary to detect parents with desirable traits that mainly depend on the action of genes controlling the trait under improvement, combining ability, and genetic makeup of the parents. Heterosis can also be used to pool the desirable genes from genetically divergent varieties and these divergent parents could be detected by molecular studies. Ten tolerant and five susceptible tester lines were selected, crossed, and tested for genetic diversity using simple sequence repeat primers. We identified two parents (A-10.8 and G-60) that showed maximum (46.7%) genetic dissimilarity. On an average 3.1 alleles per locus were detected for twenty pair of primers. Evaluation of mean values revealed that under stress conditions the mean performances of the genotypes were reduced for all traits under study. Parent A-10.8 was consistent as a good general combiner for achene yield per plant under both non-stress and stress conditions. Line A-10.8 in the hybrid A-10.8 x G-60 proved to be a good combiner as it showed negative specific combining ability (SCA) effects for plant height and internodal length and positive SCA effects for head weight, achene yield per plant, and membrane stability index. Valuable information on gene action, combining ability, and heterosis was generated, which could be used in further breeding programs.

Yield and photosynthetic attributes of sunflower cultivars grown under supplemental irrigation in the semiarid region of the Brazilian Northeast

“…Sunflower (Helianthus annuus L.) stands out among oilseeds as it contributes for about 12% of the world's edible oil production (Saba et al, 2016). The world demand for sunflower oil has been increasing on average by 1.8% per year, whereas the internal demand in Brazil increases on average at 13% per year (Rosa et al, 2009).…”

“…Some authors categorized the sunflower as a low to medium drought sensitive crop due to its welldeveloped root system, the capacity to avoid transient wilting, and ability to withstand short periods of severe soil-water deficit (Saba et al, 2016;Hussain et al, 2018). However, long periods of deficit at any growth period cause leaf drying and diminish the plant photosynthetic performance with a subsequent reduction of seed yield (Ghaffari et al, 2012;Pekcan et al, 2015).…”

Gene action of achene yield traits in sunflower under drought stress condition

“…Sunflower can tolerate water stress due to well established rooting system and have ability to avoid transitory wilting. Drought tolerant genotypes having less water requirement are the need of time to persist against drought stress (Saba et al, 2016). The hybrids of sunflower have high genetic potential for yield and good quality oil to fill up the gap between demand and supply of edible oil in the country (Manzoor et al, 2016).…”

Genetic diversity of sunflower genotypes under drought stress by principle component analysis

“…Sunflower is used as important oilseed crop due to judicious crop production requirement and good quality oil (DEMIR et al, 2006). Due to high percentage of oil 35-45 % in sunflower seed, it can reduce the gap of consumption and production in the country (SABA et al, 2016). Development of drought tolerant genotypes from diverse germplasm of sunflower would be helpful to overcome the deficiency of oilseed requirement in the country (AHMAD et al, 2009).…”