Characterization for Drought Tolerance and Physiological Efficiency in Novel Cytoplasmic Male Sterile Sources of Sunflower (Helianthus annuus L.)

Abstract

Sunflower is sensitive to drought, and furthermore, sunflower hybrids display limited cytoplasmic diversity. In addition, the wild cytoplasmic sources of sunflower are not well explored for their potential to introduce drought tolerance into newly developed hybrids. Therefore here, we carried out a Line × Tester-based genetic study using 19 sunflower genotypes representing, 13 cytoplasmic male sterile (CMS) lines from wild and conventional sources, 2 maintainer lines, and 4 restorer lines. The CMS and maintainer lines were crossed with restorer lines to develop sixty F1 hybrids. The parents and their hybrids were evaluated under two water regimes, normal irrigation and drought stress (i.e., withholding water). A total of twelve important plant descriptors were studied over a period of two years and the significant differences between parents and hybrids are reported here. More specifically, hybrid lines were higher in average values for all the descriptors. The contribution of female parent was more prominent in the expression of traits in hybrids as compared to male parents. The CMS sources varied significantly regarding seed yield per plant and other physiological traits. Proline content in the leaves of all the genotypes was three times higher in the water stress regime. Accession CMS-PKU-2A was identified as the best general combiner for leaf area and specific leaf weight., whereas CMS-234A was the best general combiner for biological yield and photosynthetic efficiency under both conditions. The cross combinations CMS-ARG-2A × RCR-8297, CMS-234A × P124R, and CMS-38A × P124R were found significant for biological yield, seed yield and oil content under both environments. Overall, this study provides useful information about the cytoplasmic effects on important sunflower traits and drought stress tolerance.

Understanding the genetics of important traits in quality protein maize (Zea maysL.) by Line × Tester analysis

“…Hybrid\s showed maximum contribution over the line and tester for all the traits. Similar finding reported by [38].…”

Line × Tester Analysis for Morphological and Fruit Biochemical Traits in Eggplant (Solanum melongena L.) Using Wild Relatives as Testers

“…In eggplant, the earliest reports of the estimation of combining ability effects date back to the late 1940s [23]. However, few studies have dealt with the estimations of CGA and SCA in crosses with wild relatives [24]. In a recent study using a diallel cross in which one accession of the wild eggplant relative S. insanum was included, we found that GCA and SCA estimates were significant for most of the morphological traits.…”

Heterotic Effect of Different Cytoplasmic Combinations in Sunflower Hybrids Cultivated Under Diverse Irrigation Regimes

“…In this work, the CMS source H. argophyllus was observed to have a negative heterotic effect, which is suitable for dwarf plant-type hybrid. The results indicated a positive influence of cytoplasmic sources on heterosis for head diameter, particularly under the water stress environment, which should be exploited to develop high-yielding hybrids suitable for growing under moisture stress environments [5]. Seed yield is one of the most critical traits for sunflower breeders.…”

“…Table 9. The list of genotypes and their interspecific hybrids (n = 48) used in the study as adapted from Tyagi et al [5].…”

“…Sunflower hybrids are preferred over varietal populations as hybrids offer several benefits in terms of growth, development, synchronous flowering, early maturity, higher seed setting, increased productivity, fewer harvest losses, and uniform seed moisture content for storage purposes [4]. Therefore, breeding efforts in sunflower are more focused on exploitation of heterosis, which has been established as a useful tool where genetically divergent parents result in highly productive sunflower hybrids with agronomically superior traits [5]. Genetic divergence among parents of a hybrid combination is a prerequisite for hybrid superiority, thus making genetic diversity evaluation an essential component of plant breeding programs [6].…”