Response surface analysis of the effects of seeding rates, N-rates and irrigation frequencies on durum wheat I. Grain yield and yield components

1988 ◽  
Vol 17 (3) ◽  
pp. 197-218 ◽  
Author(s):  
Y. P. Puri ◽  
M. F. Miller ◽  
R. N. Sah ◽  
K. G. Baghott ◽  
Elias Freres-Castel ◽  
...  
2013 ◽  
Vol 64 (10) ◽  
pp. 957 ◽  
Author(s):  
S. Dura ◽  
M. Duwayri ◽  
M. Nachit ◽  
F. Al Sheyab

Durum wheat is one of the most important staple food crops, grown mainly in the Mediterranean region where its productivity is drastically affected by salinity. The objective of this study was to identify markers associated with grain yield and its related traits under saline conditions. A population of 114 F8 recombinant inbred lines (RILs) was derived by single-seed descent from a cross between Belikh2 (salinity-tolerant variety) and Omrabi5 (less salinity tolerant) was grown under non-saline and saline conditions in a glasshouse. Phenotypic data of the RILs and parental lines were measured for 15 agronomic traits. Association of 96 simple sequence repeat (SSR) loci covering all 14 chromosomes with 15 agronomic traits was analysed with a mixed linear model. In total, 49 SSR loci were significantly associated with these traits. Under saline conditions, 12 markers were associated with phenological traits and 19 markers were associated with yield and yield components. Marker alleles from Belikh2 were associated with a positive effect for the majority of markers associated with yield and yield components. Under saline condition, five markers (Xwmc182, Xwmc388, Xwmc398, Xbarc61, and Xwmc177) were closely linked with grain yield, located on chromosomes 2A, 3A, 3B, 4B, 5A, 6B, and 7A. These markers could be used for marker-assisted selection in durum wheat breeding under saline conditions.


2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Hayelom Berhe ◽  
Ashagrie Zewdu ◽  
Kebebew Assefa

A field experiment was conducted to assess the influence of N fertilizer rates on growth, grain yield and yield components of Tef [Eragrostis tef (Zucc.) Trotter], in 2017 main cropping season. Three tef varieties (Kora, Boset and Asgori) and five Nitrogen rates (0, 30, 60, 90 and 120kg N ha-1) were used in Randomize Completed Block Design with three replications with the same dose of Triple Super Phosphate. The total and productive tiller number were highly (P<0.01) significantly affected by varieties. The control plot had maximum days to heading and this may be due to nitrogen fixation may exist and its availability may be deficient in the soil. The less response to the N rate may be due to variability of fertility or soil N content, and genetically difference between varieties. From means of varieties, the early flowerings of Boset and Asgori varieties were 101.4 and 103.79 days to maturity, respectively, but Kora (108.9 days) was late matured. Kora had maximum plant height (135.9cm) and panicle length (56.07cm) followed by Boset (115.1cm) and (42.49cm) respectively. The lodging index was affected by N rates and Kernel weight was highly significantly (P<0.01) affected only by varieties. The highest mean of thousand kernel weight (0.3387) was noted from Asgori variety. The grain yield was decreased with N rates and a better grain yield was obtained at 60-90kg N ha-1. Overall N rates indicated that, both Kora (1800) and Boset (1883) had a better grain yield in kg ha-1, but Asgori had lowest grain yield (1560kg ha-1). Based on the economic point of view, it would be more profitable to use 60kg N ha-1 N rates.


2007 ◽  
Vol 145 (3) ◽  
pp. 239-248 ◽  
Author(s):  
K. F. SOLOMON ◽  
M. T. LABUSCHAGNE ◽  
C. D. VILJOEN

The objectives of the present study were to evaluate heterosis for grain yield and yield components in durum wheat, and to assess the prediction potential of amplified fragment length polymorphism (AFLP) based and agronomic trait based genetic distances (GD and MD, respectively) to F1 performance, mid parent heterosis (MPH), and specific combining ability effects (SCA) under well-watered and moisture stress conditions. Six parental genotypes with different responses to moisture stress and their 15 F1 crosses were evaluated for their responses to moisture stress conditions in a glasshouse. Some cross combinations showed significant MPH for grain yield and yield components. The expression of heterosis for grain yield was greater under moisture stress conditions than under well-watered conditions. Cluster analysis of the parental lines based on agronomic performance under stress conditions was similar to cluster analysis result based on AFLP marker profiles. F1 performance was strongly correlated to both SCA effects and MPH under both stress and well water conditions. The correlation between SCA and MPH was very high under both treatment conditions for all traits. Correlation between GD and MD was significant only under stress conditions. Positive correlation was found only for the association between GD v. F1 performance and GD v. SCA effects for harvest index (HI) under well-watered conditions. None of the correlations between MD and SCA effects were significant. The absence of association between GD and heterosis for yield and most agronomic traits implied that heterozygosity per se diversity is not a good predictor of heterosis or F1 performance under both well-watered and stressed conditions.


2001 ◽  
Vol 29 (3-4) ◽  
pp. 237-244 ◽  
Author(s):  
A. Blanco ◽  
C. Lotti ◽  
R. Simeone ◽  
A. Signorile ◽  
V. De Santis ◽  
...  

Agronomy ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 115 ◽  
Author(s):  
Xudong Song ◽  
Guisheng Zhou ◽  
Bao-Luo Ma ◽  
Wei Wu ◽  
Irshad Ahmad ◽  
...  

: Understanding the interaction between salinity and nitrogen (N) nutrition is of great economic importance to improve plant growth and grain yield for oat plants. The objective of this study was to investigate whether N application could alleviate the negative effect of salinity (NaCl) stress on oat physiological parameters and yield performance. Two oat genotypes with contrasting salt tolerance response (6-SA120097, a salt-tolerant genotype SA and 153-ND121147, salt-sensitive ND) were grown under four N rates (0, 100, 200, and 400 mg N pot−1) in non-saline and saline (100 mM NaCl) conditions. The results showed that salinity, N fertilization and their interaction significantly affected the photosynthetic rate, transpiration rate, agronomic nitrogen use efficiency (aNUE), physiological nitrogen efficiency (pNUE) and apparent nitrogen recovery (ANR), seed number, and grain yield. Saline stress reduced gas exchange rate, nitrogen use efficiency (NUE), grain yield, and yield components. N fertilization increased photosynthetic productivity and chlorophyll fluorescence, resulting in improved grain yields and yield components for both genotypes. On average, the photosynthetic rate was increased by 38.7%, 74.1%, and 98.8% for SA and by 49.8%, 77.6%, and 110% for ND, respectively, under the N rates of 100, 200, and 400 mg N pot−1, as compared with non-fertilized treatment. In addition, grain yield was increased by 80.6% for genotype SA and 88.7% for genotype ND under higher N application rate (200 mg N pot−1) in comparison with the non-nitrogen treatment. Our experimental results showed that an increase of N supply can alleviate the negative effects induced by salinity stress and improved plant growth and yield by maintaining the integrity of the photosynthesis and chlorophyll fluorescence processes of oat plants, which provides a valuable agronomic strategy for improving oat production in salt-affected soils.


Author(s):  
Turki Al-Khalifah ◽  
Abdul Aabid ◽  
Sher Afghan Khan ◽  
Muhammad Hanafi Bin Azami ◽  
Muneer Baig

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Patrick Schwarz ◽  
Anne-Laure Bidaud ◽  
Eric Dannaoui

AbstractThe in vitro interactions of isavuconazole with colistin were evaluated against 15 clinical Candida auris isolates by a microdilution checkerboard technique based on the EUCAST reference method for antifungal susceptibility testing and by agar diffusion using isavuconazole gradient concentration strips with or without colistin incorporated RPMI agar. Interpretation of the checkerboard results was done by the fractional inhibitory concentration index and by response surface analysis based on the Bliss model. By checkerboard, combination was synergistic for 93% of the isolates when interpretation of the data was done by fractional inhibitory concentration index, and for 80% of the isolates by response surface analysis interpretation. By agar diffusion test, although all MICs in combination decreased compared to isavuconazole alone, only 13% of the isolates met the definition of synergy. Essential agreement of EUCAST and gradient concentration strip MICs at +/− 2 log2 dilutions was 93.3%. Antagonistic interactions were never observed for any technique or interpretation model used.


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