Durum wheat is a good source of protein. A grain protein content of 13% for durum is a standard in quality throughout the grain industry (Riley et al. 1998). Protein content like other traits in wheat is known to be affected by genetic and environmental factors mainly location (Bement et al. 2003). In this study we evaluated a set of 25 genotypes comprising introduction from CIMMYT and advanced lines developed through hybridization by the Ethiopian National Durum Wheat Research Project (NDWP) for protein content over six testing locations, representing the wheat agro-ecologies in the country. The experiments were conducted in a randomised complete block design (RBD) with three replications each. Plot size was kept at 2 m
. Grain protein content was analyzed following Kjeldahl method (A.A.C.C. 1983). Stability analysis was done according to Eberhart and Russel (1966) model and effect of locations and its interaction with genotypes were estimated following additive main effects and multiplicative interaction (AMMI) model. The mean grain protein content varied from 11.61 to 13.52% among the genotypes. Only three genotypes, namely CD98206, DZ3117 and DZ-04-118 attained higher grain protein content than standard 13.00%. Stability analysis revealed that all but three genotypes were observed to be predictable. DZ 2212-1BS was found suitable for favorable environments. Genotype CD97383 was found sensitive to change in environment. Eight genotypes were identified as stable. Genotypes DZ3117 was found to be the best having maximum protein content recorded at AlemTena location and higher yield with stable performance across locations. AMMI analysis revealed that the first two significant IPCA scores together explained 73.55% of the total interaction variance. Biplot graphical analysis showed Alem Tena as the best location followed by Debre Zeit and Minjar in terms of average protein content of genotypes. Genotype DZ1669-1AK scored zero and could be considered as stable and wide adaptable having protein content higher than the general mean. The graphical analysis of IPCA 1 and IPCA 2 further revealed that this genotype was relatively close to origin zero. Genotype DZ-04-118 was adapted to Debre Zeit and Minjar while a large numbers of genotypes with negative IPCA score were adapted to Akaki and Chefe Donsa locations. Genotype DZ3117 had specific adaptability to Alem Tena location. High protein but low grain yield at Alem Tena may be due to the drought occurrence during grain filling period.
Authors:B. Vaezi, A. Pour-Aboughadareh, R. Mohammadi, M. Armion, A. Mehraban, T. Hossein-Pour, and M. Dorii
Successful production and development of stable and adaptable cultivars only depend on the positive results achieved from the interaction between genotype and environment that consequently has significant effect on breeding strategies. The objectives of this study were to evaluate genotype by environment interactions for grain yield in barley advanced lines and to determine their stability and general adaptability. For these purposes, 18 advanced lines along with two local cultivars were evaluated at five locations (Gachsaran, Lorestan, Ilam, Moghan and Gonbad) during three consecutive years (2012–2015). The results of the AMMI analysis indicated that main effects due to genotype (G), environment (E) and GE interaction as well as four interaction principal component axes were significant, representing differential responses of the lines to the environments and the need for stability analysis. According to AMMI stability parameters, lines G5 and G7 were the most stable lines across environments. Biplot analysis determined two barley mega-environments in Iran. The first mega-environment contained of Ilam and Gonbad locations, where the recommended G13, G19 and G1 produced the highest yields. The second mega-environment comprised of Lorestan, Gachsarn and Moghan locations, where G2, G9, G5 and G7 were the best adapted lines. Our results revealed that lines G5, G7, G9 and G17 are suggested for further inclusion in the breeding program due to its high grain yield, and among them G5 recommended as the most stable lines for variable semi-warm and warm environments. In addition, our results indicated the efficiency of AMMI and GGE biplot techniques for selecting genotypes that are stable, high yielding, and responsive.
Authors:S. Sareen, R. Munjal, N. Singh, B. Singh, R. Verma, B. Meena, J. Shoran, A. Sarial, and S. Singh
Terminal heat, which is referred as increase in temperature during grain filling, is one of the important stress factors for wheat production. Current estimates indicate that wheat crop grown on around 13.5mha in India is affected by heat stress. In order to meet the challenges of high temperature ahead of global warming, concerted efforts are needed to evaluate germplasm for heat tolerance and identify and develop genotypes suitable for such stressed environments. The advanced wheat genotypes developed for stress and normal environments by different research centers were evaluated across 7 locations representing varied agroclimatic zones during 2007–08 and 2008–09 to study their adaptability for heat stress and non-stress environments. The additive main effects and multiplicative interaction analysis for G × E interactions revealed differences amongst locations to phenology and grain yield. Genotype RAJ 4083 developed for cultivation under late sown conditions in peninsular zone was also found adaptable to timely sown conditions. Similarly, HD 2733 a cultivar of NEPZ timely sown conditions and PBW 574 an advanced breeding line of NWPZ late sown conditions was found adapted to Peninsular zone. The cultivar RAJ 3765 showed specific adaptability to Pantnagar in NWPZ. Genotype NW 3069 developed for NEPZ timely sown conditions have shown adaptability to number of locations; timely sown conditions at Karnal and Hisar in NWPZ and Niphad in PZ. Likewise, WH 1022 developed for NEPZ late sown conditions exhibited specific adaptability to all timely sown locations in NWPZ.
Authors:I. Prasad, N. Kulshreshtha, A. R. Chinchmalatpure, and D. K. Sharma
Soil salinity is one of the major environmental constraints in increasing agricultural crop production, especially wheat production in India. Screening of diverse germplasm in representative growing conditions is prerequisite for exploring traits with stable expression imparting salinity tolerance. A study was undertaken during 2011–2012 for characterizing wheat germplasm in three environments representing growing conditions of crop in Northern parts of India, estimating inter-relationship among traits and evaluating stability of trait conferring salinity tolerance. Significant value of mean square for observed trait across the environments signified presence of large variability in genotypes. Significant yield reduction was recorded in almost all genotypes in saline environment compared to non-saline condition. Ratio of potassium and sodium ion in leaf tissue (KNA); a key salt tolerance traits was found to be significantly correlated with biomass, SPAD value and plant height. Due to the presence of significant genotype × environment interaction (G × E) for KNA, additive main effect and multiplicative interaction (AMMI) model was utilized to study stability of KNA among genotypes and environments. IPCA1 and IPCA2 were found to be significant and explained more than 99 per cent of variation due to G × E. KRICHAUFF was having maximum trait value with specific adaptation while DUCULA 4 and KRL 19 were having general adaptability. AMMI2 biplot revealed high stability of Kharchia 65 and KRL 99 across environments. E1 (timely sown, non-saline soil) recorded maximum site mean while E2 (timely sown, sodic soil) was having minimum interaction with genotypes (AMMI1 = 1.383). Thus, our studies suggest that AMMI model is also useful for estimating adaptability of traits other than yield utilized for breeding salt tolerant wheat varieties.
The genotype by
environment (GE) interaction is a major problem in the study of quantitative
traits because it complicates the interpretation of genetic experiments and
makes predictions difficult. In order to quantify GE interaction effects on the
grain yield of durum wheat and to determine stable genotypes, field experiments
were conducted with ten genotypes for four consecutive years in two different
conditions (irrigated and rainfed) in a completely randomized block design with
three replications in each environment. Combined analysis of variance exhibited
significant differences for the GE interaction, indicating the possibility of
stable entries. The results of additive main effect and multiplicative
interaction (AMMI) analysis revealed that 12% of total variability was
justified by the GE interaction, which was six times more than that of
genotype. Ordination techniques displayed high differences for the interaction
principal components (IPC1, IPC2 and IPC3), indicating that 92.5% of the GE sum
of squares was justified by AMMI1, AMMI2 and AMMI3, i.e. 4.5 times more than
that explained by the linear regression model. The results of the AMMI model
and biplot analysis showed two stable genotypes with high grain yield, due to
general adaptability to both rainfed and irrigated conditions, and one with