Genotype by environment interaction analysis of wheat (Triticum aestivum L.) grain yield under rain-fed conditions in Zambia

Understanding genotype by environment interaction (GEI) is important for crop improvement because it aids in the recommendation of cultivars and the identification of appropriate production environments. The objective of this study was to determine the magnitude of GEI for the grain yield of wheat grown under rain-fed conditions in Zambia by using the additive main effects and multiplicative interaction (AMMI) model. The study was conducted in 2015/16 at Mutanda Research Station, Mt. Makulu Research Station and Golden Valley Agricultural Research Trust (GART) in Chibombo. During2016/17, the experiment was performed at Mpongwe, Mt. Makulu Research Station and GART Chibombo, Zambia. Fifty-five rain-fed wheat genotypes were evaluated for grain yield in a 5 × 11 alpha lattice design with two replications. Results revealed the presence of significant variation in yield across genotypes, environments, and GEI indicating the differential performance of genotypes across environments. The variance due to the effect of environments was higher than the variances due to genotypes and GEI. The variances ascribed to environments, genotypes, and GEI accounted for 45.79%, 12.96%, and 22.56% of the total variation, respectively. These results indicated that in rain-fed wheat genotypes under study, grain yield was more controlled by the environment than by genetics. AMMI biplot analysis demonstrated that E2 was the main contributor to the GEI given that it was located farthest from the origin. Furthermore, E2 was unstable yet recorded the highest yield. Genotype G47 contributed highly to the GEI sum of squares considering that it was also located far from the origin. Genotypes G12 and G18 were relatively stable because they were situated close to the origin. Their position indicated that they had minimal interaction with the environment. Genotype 47 was the highest-yielding genotype but was unstable, whereas G34 was the lowest-yielding genotype and was unstable.

Formulasi Fast Disintegrating Tablet Ekstrak Etanol Daun Salam dengan Kombinasi Crospovidone dan Croscarmellose Sodium sebagai Superdisintegrants

Pengembangan formulasi ekstrak daun Salam (Syzygium polyanthum W.) sebagai antihiperlipidemia yang mampu hancur cepat setelah diletakkan di atas lidah sangat diperlukan untuk mempercepat onset obat dan memberikan kenyamanan terutama pada pasien hiperlipidemia usia lanjut yang sulit menelan obat. Tujuan dari penelitian ini untuk mengetahui komposisi perbandingan superdisintegrants crospovidone dan croscarmellose sodium yang mampu menghasilkan sifat fisik Fast Disintegrating Tablet (FDT) yang optimum. Pembuatan FDT menggunakan metode granulasi basah dengan variasi konsentrasi crospovidone dan croscarmellose sodium dalam rentang 2%-5%. Hasil uji sifat fisik FDT dianalisis menggunakan metode Simplex Lattice Design (SLD) program Design Expert 10.1.). Kombinasi kedua superdisintegrants dapat mempengaruhi respon sifat fisik yaitu mampu menurunkan kekerasan, waktu disintegrasi, waktu pembasahan dan meningkatkan kerapuhan FDT ekstrak daun salam. Formula optimum didapat pada kombinasi crospovidone dan croscarmellose sodium dengan perbandingan 25 mg : 10 mg dalam setiap 500 mg tablet. Formula optimum tersebut memiliki kekerasan 4,21 kg, kerapuhan 0,52%, waktu pembasahan 106,65 detik, dan waktu hancur 55,73 detik. Hasil analisis dengan one sample t-test menunjukkan persamaan SLD valid digunakan untuk menyusun formula yang memberikan parameter-parameter optimum FDT.

Agro-morphological traits-based genetic diversity assessment in Ethiopian barley (Hordeum vulgare L.) landrace collections from Bale highlands, Southeast Ethiopia

Background Cultivated barley (Hordeum vulgare L.) is one of the world’s important cereal crops. Ethiopia is claimed to be the centre of origin due to its high phenotypic diversity and flavonoid patterns. It is widely cultivated on subsistence bases and important in supporting the livelihood of local poor. However, the local landraces are currently under threat of severing genetic erosion. Hence, assessing the extents of its genetic diversity is timely in improvement and conservation. Methodology 120 representative cultivated barley landraces have been collected from Bale highlands, Ethiopia, and tested at two locations using alpha lattice design. Data were collected on 21 agro-morphometric traits and analysed using MINITAB 19, SAS 9.4 and FigTree v1.4.3. Results Most morphotypes in each of the qualitative traits considered and mean performance values in most of the quantitative traits revealed wide range of variations suggesting existence of phenotypic diversity among the landraces. Analysis of variance also showed significant variations among the landraces. All the traits, except days to maturity and plant height showed a significant variation for location and treatment-location interactions revealing the high impact of environmental conditions on the variations. Estimates of the variance components also revealed a wider range of variations in most of the traits considered with eventual medium to low genotypic (GCV), phenotypic (PCV) and genotype–environment coefficients of variation (GECV). Estimates of heritability in broad sense (H2) is low (< 40%) in all the traits except in days to maturity. Grouping of the landraces showed poor geographic areas of collection-based pattern suggesting extensive gene flow among the areas. Conclusion The landraces evaluated in the present study showed high morphological diversity. However, the effect of environment factor is pronounced and thus, multiple locations and years with large number of samples must be considered to exploit the available genetic-based variations for breeding and conservation of the crop.

Genetic analysis of grain yield and yield-attributing traits in navy bean (Phaseolus vulgaris L.) under drought and optimal environments

Knowledge of the genetic basis of navy bean (Phaseolus vulgaris L.) performance under drought stress (DS) is important for planning appropriate breeding and selection strategies in DS environments. Twenty-eight F2 progenies generated from an 8 x 8 half-diallel mating design were evaluated to determine combining ability effects and mode of gene action of grain yield (GYD) and yield attributing traits in navy bean under DS and non-stressed (NS) conditions. The experiments were conducted in two locations in a 6 x 6 square lattice design with two replications during the 2020 dry season. There were significant (p < 0.001; p < 0.05) positive correlations for number of pods per plant (NPPP), number of seeds per plant (NSPP) and 100-seed weight (SW) with GYD under both DS and NS. General and specific combining ability (GCA; SCA) effects were significant (p < 0.05) under both DS and NS for most traits indicating the importance of both additive and non-additive gene effects in the expression of the traits. Parents with best combining ability for most of the studied traits were G1, G7, G6 and G8 under NS, and G3, G4, G7 and G8 under DS. The most promising progenies with high values for GYD and its component traits under DS were G2 X G3, G2 X G8, G4 X G5, G4 X G8, and G6 X G8. Good general and specific combiners with high significant positive effects under DS should be used further in breeding for moisture stress tolerance.

Genotype by Environment Interaction and Grain Yield Stability of Drought Tolerant Cowpea landraces in Ethiopia

Cowpea is one of the most important indigenous food and forage legumes in Africa. It serves as a primary source of protein for poor farmers in drought-prone areas of Ethiopia. The crop is used as a source of food, and insurance crop during the dry season. Cowpea is adaptable to a wide range of climatic conditions. Despite this, the productivity of the crop is generally low due to lack of stable and drought tolerant varieties. In this study, 25 cowpea genotypes were evaluated in five environments using a triple lattice design during the 2017 and 2018 main cropping seasons. The objectives of this study were to estimate the magnitude of genotype by environment interaction (GEI) and grain yield stability of selected drought tolerant cowpea genotypes across different environments. The additive main effect and multiplicative interaction (AMMI) model indicated the contribution of environment, genotype and GEI as 63.98 6%, 2.66% and 16.30% of the total variation for grain yield, respectively. The magnitudes of the GEI sum of squares were 6.12 times that of the genotypes for grain yield. The IPCA1, IPCA2 and IPCA3 were all significant and explained 45.47%, 28.05% and 16.59% of the GEI variation, respectively. The results from AMMI, cultivar superior measure (Pi), genotype plus genotype-by-environment (GGE) biplot yield stability index (YSI), and AMMI stability value (ASV) analyses identified NLLP-CPC-07-145-21, NLLP-CPC-103-B and NLLP_CPC-07-54 as stable and high yielding genotypes across environments. Thus, these genotypes should be recommended for release for production for drought prone areas. NLLP-CPC-07-143, Kanketi and CP-EXTERETIS were the least stable. The AMMI1 biplot showed that Jinka was a high potential and favorable environment while Babile was an unfavorable environment for cowpea production.