Enhancing Drought Tolerance and Striga hermonthica Resistance in Maize Using Newly Derived Inbred Lines from the Wild Maize Relative, Zea diploperennis

Abstract

Recurrent drought and Striga hermonthica (Del.) Benth parasitism constrains maize production in sub-Saharan Africa (SSA). Transfer of resistance genes from wild relatives can improve resistance to drought and Striga in tropical maize. The objectives of this study were to (i) determine the combining ability of 12 extra-early yellow maize inbreds derived from Zea diploperennis and tropical maize germplasm; (ii) classify the inbreds into heterotic groups using heterotic grouping based on the general combining ability (GCA) of multiple traits (HGCAMT) method; (iii) examine hybrid performance under contrasting environments; and (iv) examine the stability of hybrid combinations involving the inbreds. Sixty-six diallel crosses involving the inbreds plus four checks were evaluated for two years under drought, Striga-infested and rainfed environments in Nigeria. Significant differences (p < 0.05) were observed for the effects of genotype, environment, genotype × environment, GCA and specific combining ability (SCA) on grain yield and other measured traits. Inbred lines such as TZdEEI 7 × TZEEI 63 derived from Z. diploperennis and tropical germplasm exceeded the checks by a range of 28 to 41%. Across environments, the hybrid TZdEEI 1 × TZdEEI 7, which was derived from Z. diploperennis, was the highest-yielding with a grain yield of 4302 kg ha−1. The results revealed the predominance of GCA over SCA effects for most measured traits, suggesting that additive gene action governed the inheritance of Striga resistance and drought tolerance related traits in the inbreds. The 12 inbreds were classified into three heterotic groups, while TZEEI 79 and TZdEEI 7 were identified as inbred testers and TZdEEI 7 × TZEEI 12 as a single-cross tester across environments. Hybrid TZdEEI 9 × TZEEI 79 was the highest-yielding and most stable. Other promising hybrids were TZdEEI 7 × TZEEI 79, TZdEEI 1 × TZdEEI 7 and TZdEEI 12 × TZEEI 95. These hybrids should be extensively tested on-farm for potential commercialization in SSA. Overall, our results highlighted the importance of harnessing beneficial alleles from wild relatives of maize for improvement of resistance to Striga and tolerance to drought in adapted maize germplasm.

Estimating the combining ability and genetic parameters for growth habit, yield, and fiber quality traits in some Egyptian cotton crosses

“…Given that these genotypes have good general combining ability, female parental genotypes with a great potential to transmit on desirable traits to their cross progeny could be used as a substantial material to improve the qualities of interest [ 11 , 42 ]. The significant GCA effects reported in the current investigation were consistent with those found in prior studies [ 31 , 60 – 62 ]. Positive and significant GCA effects observed in the current study for female parental genotypes and testers are significantly vital.…”

Evaluation of Some Maize-Teosinte Hybrids and Their Parents Under Water Stress Conditions

“…Also, cross (L 3 × T 3 ) showed good SCA effect for ears dry weight/ plant (under stress irrigation regime). In this concern, Sakr and Ghazy (2010), Abdel-Aty et al (2013), Hatab (2014), Ghazy (2016), Habeba (2019) and Shaibu et al (2021) found highly significant positive SCA effects in maize × teosinte crosses in some growth characters and forage productivity.…”

“…This means that those genotypes could be used as donors in program to improve the growth characters and forage productivity of maize and teosinte under any tested irrigation regimes. Rady (2007), Sakr and Ghazy (2010), Meseka et al, (2011), Abd El-Zaher (2016) and Shaibu et al (2021) they found positive GCA in some maize and teosinte genotypes in some growth characters and forage productivity.…”

Harnessing plant resistance against Striga spp. parasitism in major cereal crops for enhanced crop production and food security in Sub-Saharan Africa: a review

“…Host plant resistance remain the most sustainable, economically, and eco-friendly method to control the parasitic weeds. Striga-resistance is a polygenic trait that requires combining whole-genome information (Badu-Apraku et al, 2020a;Shaibu et al, 2021). Genotyping and phenotyping are therefore critical to correlate the resistance-associated traits with particular gene loci.…”