Quantitative analysis of gene actions controlling root length under water stress in spring wheat (Triticum aestivum L.) genotypes

2016 ◽  
Vol 67 (5) ◽  
pp. 489 ◽  
Author(s):  
Habtamu Ayalew ◽  
Hui Liu ◽  
Guijun Yan

Understanding the genetic control of agronomic traits is important in designing crop improvement programs. Study was conducted to analyse the genetic control of root length under water stress. A full diallel cross of four spring wheat lines, along with their F1 progenies was evaluated under –0.82 MPa water stress in a hydroponic culture. Analysis of variance showed highly significant (P < 0.01) difference among the parental lines and their F1 progenies. Genotypes Santa Elena, Colotana 296–52 and Pato showed comparable longer roots whereas Tincurrin grew significantly (P < 0.05) shorter roots. Genotypes with long roots were found to have more dominant genes than those with shorter roots. Both general and specific combining abilities were highly significant (P < 0.01) indicating the importance of additive and dominant gene effects in the control of root length under water stress. Genotype Santa Elena was found to be the best general combiner whereas the specific cross Santa Elena × Pato was the best hybrid. Moderate narrow-sense heritability (38%) was observed indicating the possibility of improving root length under water stress. The highly significant specific combining ability value (dominant genetic control) suggests that genotypes with more dominant genes should be selected as parents for hybridisation and the hybrid wheat approach might be helpful in improving water stress resistance.

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1193
Author(s):  
Muhammad Sohail Saddiq ◽  
Shahid Iqbal ◽  
Muhammad Bilal Hafeez ◽  
Amir M. H. Ibrahim ◽  
Ali Raza ◽  
...  

Salinity is a leading threat to crop growth throughout the world. Salt stress induces altered physiological processes and several inhibitory effects on the growth of cereals, including wheat (Triticum aestivum L.). In this study, we determined the effects of salinity on five spring and five winter wheat genotypes seedlings. We evaluated the salt stress on root and shoot growth attributes, i.e., root length (RL), shoot length (SL), the relative growth rate of root length (RGR-RL), and shoot length (RGR-SL). The ionic content of the leaves was also measured. Physiological traits were also assessed, including stomatal conductance (gs), chlorophyll content index (CCI), and light-adapted leaf chlorophyll fluorescence, i.e., the quantum yield of photosystem II (Fv′/Fm′) and instantaneous chlorophyll fluorescence (Ft). Physiological and growth performance under salt stress (0, 100, and 200 mol/L) were explored at the seedling stage. The analysis showed that spring wheat accumulated low Na+ and high K+ in leaf blades compared with winter wheat. Among the genotypes, Sakha 8, S-24, W4909, and W4910 performed better and had improved physiological attributes (gs, Fv′/Fm′, and Ft) and seedling growth traits (RL, SL, RGR-SL, and RGR-RL), which were strongly linked with proper Na+ and K+ discrimination in leaves and the CCI in leaves. The identified genotypes could represent valuable resources for genetic improvement programs to provide a greater understanding of plant tolerance to salt stress.


2019 ◽  
Vol 48 (3) ◽  
pp. 521-527
Author(s):  
Muhammad Sajjad Iqbal ◽  
Abdul Ghafoor ◽  
Muhammad Akbar ◽  
Shamim Akhtar ◽  
Sammer Fatima ◽  
...  

Thirty two genotypes of Nigella sativa L. were evaluated for three consecutive years which showed significant differences for all the traits indicating high level of genetic variation. Heritability in broad sense ranged from 0.28 to 0.98 and the highest heritability was calculated for days to maturity and days to flowers. Grain yield was positively associated with plant height, capsule weight, capsule length, root length, whereas negatively with capsule width and 1000-seed weight that required the use of novel breeding techniques to break this undesired linkage to improve grain yield in N. sativa. Path coefficient indicated that direct effects of all the traits were positive except days to first flower, days to 50% flowers, flowering duration, number of capsules, root weight and harvest index. The characters exhibiting correlation along with direct effect towards grain yield viz., days to maturity, capsule weight, capsule length and root length should be given more preference while selecting high yielding N. sativa genotypes for future crop improvement programs.


2015 ◽  
Vol 95 (2) ◽  
pp. 377-385 ◽  
Author(s):  
Maryam Golabadi ◽  
Pooran Golkar ◽  
Abdolreza Eghtedary

Golabadi, M., Golkar, P. and Eghtedary, A.-R. 2015. Combining ability analysis of fruit yield and morphological traits in greenhouse cucumber (Cucumis sativus L.). Can. J. Plant Sci. 95: 377–385. Knowledge about the genetic control of the different quantitative characters related to fruit yield and its components is still insufficient in greenhouse cucumbers. This information is useful in planning breeding programs in this economically important crop. In this study, the genetics of morphological traits and fruit yield was investigated using a 9×9 full diallel population of cucumbers for the greenhouse market. Data were collected on internode length, leaf length, leaf width, fruit length, fruit diameter, number of fruits per plant, yield per fruit and yield per plant. Variance components showed that both the additive and the dominant gene effects played significant roles in the genetic control of the traits studied. Genetic control of internode length, leaf width and number of fruits per plant was accomplished by additive effects. The significant mean squares of reciprocal crosses for all of the studied traits suggested that maternal inheritance also played an important role in the inheritance of these traits. Significant general combining ability for fruit yield revealed that both selection and hybridization methods would lead to desirable genetic improvements in cucumber through accumulation of desirable alleles from parents in the target genotype, but that hybridization would be preferred.


Author(s):  
R.C. Meena ◽  
Supriya Ambawat ◽  
C. Tara Satyavathi ◽  
Moola Ram ◽  
Vikas Khandelwal ◽  
...  

Background: Pearl millet [Pennisetum glaucum (L.) Br.] is the most widely grown staple food of majority of poor and small land holders in Asia and Africa. It is also consumed as feed and fodder for livestock. It is the sixth most important cereal crop in the world next to maize, rice wheat, barley and sorghum. The temperature is one of the key climatic factors and has profound effect on the growth and development of the pearl millet. It can only be managed through developing hybrid varieties which can tolerate high temperature during germination and early seedling stages.The present study aimed to identify drought tolerant genotypes of pearl millet at seedling stage. Methods: This experiment was carried out at Mandor during kharif 2018 with five selected pearl millet advanced hybrids MH 2192, MH 2224, MH 2228, MH 2354 and MH 2359 along with three checks RHB 177, MPMH 17 and 86M86 which were tested under polyethylene glycol (PEG) (5% and 10%) induced osmotic stress. Various physiological parameters were recorded 15 days after sowing and statistical analysis made using Windostat software. Result: The results revealed that shoot length, seedling dry weight, relative water content, membrane stability index and chlorophyll content decreased significantly with PEG induced water stress in all the hybrids while root length and catalase activity increased significantly under water stress. Among 5 hybrids, two hybrids viz. MH 2359 and MH 2354 performed better and found to be superior under PEG induced water stress. Thus, various drought tolerance indices may further be studied for these two hybrids and can be used in development of drought tolerant genotypes which may prove helpful for crop improvement programs of pearl millet.


Author(s):  
Pallavi Sinha ◽  
Vikas K. Singh ◽  
Abhishek Bohra ◽  
Arvind Kumar ◽  
Jochen C. Reif ◽  
...  

Abstract Key message Integrating genomics technologies and breeding methods to tweak core parameters of the breeder’s equation could accelerate delivery of climate-resilient and nutrient rich crops for future food security. Abstract Accelerating genetic gain in crop improvement programs with respect to climate resilience and nutrition traits, and the realization of the improved gain in farmers’ fields require integration of several approaches. This article focuses on innovative approaches to address core components of the breeder’s equation. A prerequisite to enhancing genetic variance (σ2g) is the identification or creation of favorable alleles/haplotypes and their deployment for improving key traits. Novel alleles for new and existing target traits need to be accessed and added to the breeding population while maintaining genetic diversity. Selection intensity (i) in the breeding program can be improved by testing a larger population size, enabled by the statistical designs with minimal replications and high-throughput phenotyping. Selection priorities and criteria to select appropriate portion of the population too assume an important role. The most important component of breeder′s equation is heritability (h2). Heritability estimates depend on several factors including the size and the type of population and the statistical methods. The present article starts with a brief discussion on the potential ways to enhance σ2g in the population. We highlight statistical methods and experimental designs that could improve trait heritability estimation. We also offer a perspective on reducing the breeding cycle time (t), which could be achieved through the selection of appropriate parents, optimizing the breeding scheme, rapid fixation of target alleles, and combining speed breeding with breeding programs to optimize trials for release. Finally, we summarize knowledge from multiple disciplines for enhancing genetic gains for climate resilience and nutritional traits.


Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 174
Author(s):  
Hui Liu ◽  
Fabio Fiorani ◽  
Ortrud Jäck ◽  
Tino Colombi ◽  
Kerstin A. Nagel ◽  
...  

Plants with improved nutrient use efficiency are needed to maintain and enhance future crop plant production. The aim of this study was to explore candidate traits for pre-breeding to improve nutrient accumulation and early vigor of spring wheat grown at high latitudes. We quantified shoot and root traits together with nutrient accumulation in nine contrasting spring wheat genotypes grown in rhizoboxes for 20 days in a greenhouse. Whole-plant relative growth rate was here correlated with leaf area productivity and plant nitrogen productivity, but not leaf area ratio. Furthermore, the total leaf area was correlated with the accumulation of six macronutrients, and could be suggested as a candidate trait for the pre-breeding towards improved nutrient accumulation and early vigor in wheat to be grown in high-latitude environments. Depending on the nutrient of interest, different root system traits were identified as relevant for their accumulation. Accumulation of nitrogen, potassium, sulfur and calcium was correlated with lateral root length, whilst accumulation of phosphorus and magnesium was correlated with main root length. Therefore, special attention needs to be paid to specific root system traits in the breeding of wheat towards improved nutrient accumulation to counteract the suboptimal uptake of some nutrient elements.


2021 ◽  
Vol 50 (2) ◽  
pp. 289-294
Author(s):  
Muhammad Sajjad Iqbal ◽  
Abdul Ghafoor

Study revealed a first report of proteomics variation in Nigella sativa L. based on analyzing 32 accessions through SDS-PAGE. Three prominent regions along eight subunits were identified. Intra specific variation was observed low whereas the sharpness of bands was high between first and second regions. It was noted that in second region there was no clear evidence of band formation in N. sativa. Prominent and sharp protein peptide bands were recorded in four accessions, namely PK-020561, PK-020609, PK-020620 and PK-020646. Further investigation of single seeds showed almost similar genetic pattern within the single accession. Five clusters were formed on the basis of Euclidean distance. Cluster-I & II contain 1, 1 accession each, likewise Cluster-III and C-IV contain 2, 2 accessions whereas Cluster-V was found diversified as consisted of 26 accessions. Two accessions PK-020878 and PK-020877 were recommended for polymorphism and crop improvement programs. Bangladesh J. Bot. 50(2): 289-294, 2021 (June)


Author(s):  
Ali Hussain Al Lawati ◽  
Saleem Kaseemsaheb Nadaf ◽  
Nadiya Abubakar Al Saady ◽  
Saleh Ali Al Hinai ◽  
Almandhar Almamari ◽  
...  

Oman is endowed with enormous diversity of important food crops that have global significance for food security and has ancient history of cultivation of bread wheat (Triticum aestivum L.) with its divergent landraces, which are useful in crop improvement. 55 indigenous Omani accessions conserved at the USDA were evaluated in the winter season (November to April) of the years 2017-2018 and 2018-2019 on loamy soil under sprinklers in augmented design with 5 check varieties in 5 replications following crop husbandry practices as per national recommendations using 9 quantitative (descriptors) and 6 qualitative traits (anthocyanin pigmentation on plant parts). The data on traits were subjected not only for PC values and D values after varimax rotation through Kaiser normalization in Principal Component Analysis (PCA) but also for Agglomerative Hierarchical Clustering (AHC). The results indicated that indigenous bread wheat accessions were significantly different (p>0.05) for all the quantitative traits except number of tillers. The multivariate analyses led to formation of four diverse clusters from PCA analyses corresponding to four quadrants of bi-plot graphs and three clusters from AHC analysis corresponding to main clades of dendrogram. The parents were selected from common accessions of distinct clusters in all the multivariate analyses for hybridization for improving characters of growth for higher yield or productivity with pigmentation on one or two plant parts useful for DUS test of varieties. The indigenous bread wheat landraces / accessions were genetically diverse and have potential for use in national crop improvement programs for earliness and higher grain productivity with distinct identification markers.


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