scholarly journals Probing of the genetic components of seedling emergence traits as selection indices, and correlation with grain yield characteristics of some tropical maize varieties

2021 ◽  
Vol 6 (1) ◽  
pp. 223-229
Author(s):  
Sunday Ayodele Ige ◽  
Omolaran Bello ◽  
Aremu Charity ◽  
Abolusoro Stephen

Abstract Ten maize varieties of tropical origin were tested at two different agro-ecological zones during the cropping season of 2007 and 2008 to investigate the genetic components of seedling emergence characteristic and correlate with grain yield and related traits in Nigeria. Heritability values were high for all traits study, indicating reliability and stability of most of the traits across different environments. Variety DMRLSR-Y had highest 300 kernel weight (105.2 g), but least grain yield and second to the least emergence percentage, indicating bigger kernel and highest kernel weight/cob but low plant stands resulted in low grain yield. Genotypic and agronomic correlation analysis revealed positive associations (p < 0.01) between grain yield and emergence percentage (E%), and 300 kernel weight; however, interval between pollen shed and silking was negatively correlated with physiological maturity period and 300 kernel weight. Improvement of this variety for higher emergence percentage is therefore predicted for higher grain yield. High values of genotypic and phenotypic coefficient of variation recorded by emergence percentage (41 and 45%) and grain yield (25 and 32%), respectively, revealed the less effects of environmental factors on the aforementioned characters, and it showed the stability and reliability of the two traits. High values of both broad sense heritability and genetic advance recorded by emergence percentage (E%) and 300 kernel weight confirmed that standard selection procedure could be used to identify superior genotypes for the two traits.

Author(s):  
Wisam Khald Sabri ◽  
Abdullah Oktem

Aims: The study was designed to elucidate the effect of different nitrogen (N) fertilizer levels on five different maize cultivars. Study Design:  A split plot experimental design in randomized complete blocks (RCBD) with three replicates. Arrangement of seven nitrogen levels and five single cross hybrids were compared. Main plots were nitrogen levels and subplots were varieties. Place and Duration of Study: College of Agricultural Engineering Sciences at the University of Duhok, Iraq. The study was undertaken fromMarch– August 2021. Methodology: At the present research, five single cross-hybrid corn varieties were used, which were: CADZ, DKC6050, DRACHMA, MYIMY and ZP6468D. Arrangement of seven nitrogen fertilizer levels were 0, 50, 100, 150, 200, 250 and 300 kg N ha−1. The following features were studied: plant height, leaf area index, thousand kernel weight, total grain yield, total chlorophyll, protein% and oil %.The collected data were projected to SAS software program for analysis. The significant differences between treatment means were calculated using Duncan’s multiple ranges. Results: It was reveal that there were significant effect of different nitrogen fertilizer levels, maize genotypes as well as the interaction of nitrogen and genotype of maize (P<.01) for plant height, leaf area index, 1000 kernel weight, total grain yield, total chlorophyll and protein %. However, There were no significant differences between different maize genotypes as well as different nitrogen fertilizer levels (P>.05) with oil %, but the interaction of nitrogen and genotype of maize was significant (P<.01). Conclusion: Increasing the amount of nitrogen had better effect on studied characteristics of different maize varieties, in which adding 300 kg nitrogen had optimum results. In considering the response of maize varieties to nitrogen, the best variety was DRACHMA genotype while the worst variety was CADZ genotype, however this hybrids was superior in some traits.


1981 ◽  
Vol 97 (1) ◽  
pp. 125-134 ◽  
Author(s):  
E. O. Lucas

SUMMARYThe growth and development of two new maize hybrids (FARZ 27 and FARZ 23) were studied in density experiments located at two contiguous ecological zones in Nigeria. The range of planting density used was from 2·6 to 6·6 plants/m2. Within this range, the relationship between dry-matter yield and density was asymptotic at final harvest. At the forest location of Jago (7·3 °N, 4·2 °E), both varieties attained optimum grain yield at planting density of 4·4 plants/m2, while at the derived savannah location of Alagunmu (7·8 °N, 4 °E), FARZ 23 attained optimum grain yield at 4·4 plants/m2and FARZ 27 attained its optimum grain yield at 6·6 plants/ma2. This response of the new maize varieties to density treatments indicates that they could be planted at higher densities than are now used in the country.Differences between varieties did not quite reach statistical significance but, at both locations, FARZ 27 produced more dry matter and grain per unit area than FARZ 23. FARZ 27 gave its higher grain yield mainly by producing more seeds per unit area than FARZ 23. Physiological measurements like net assimilation rate, crop growth rate and leaf area index were also higher for FARZ 27, although there were no significant differences between the varieties at most sampling dates. The partition of dry matter was identical in both varieties, although FARZ 27 showed a slightly better balance by partitioning more assimilates to the grain. Also, there was an indication of remobilization of stored assimilates from the stem to the grain in both varieties. Both varieties produced more dry matter and grain at the derived savannah location of Alagunmu than at the forest location of Jago. Physiological measurements were also higher at the derived savannah location.


Author(s):  
V. Manimozhi Selvi ◽  
A. Nirmalakumari

Twelve accessions of littlemillet genotypes which included 10 germplasm accessions and two released check varieties were studied over five environments of rainy seasons of 2013 for their grain yield and stability. The results have shown that genotypes TNPsu 141 and TNPsu 28 had possessed around unit regression coefficient (b = 1.24 to 0.82), thus displaying average stability and are adaptable to all the above five different agro-ecological zones.  Also, these genotypes had non- significant S2di values enabling it to predict the stability. Genotypes TNPsu 17, PM 29, TNPsu 18, and IPmr 886 manifested significantly higher single plant grain yield than the standard check varieties along with regression coefficient values of greater than one expressing above-average stability. These can be performed better in a favourable environment. However, they were classified as unstable due to their significant S2 di values revealing that the performance of the genotypes was unpredictable for the given environment. These genotypes were performed better under optimum conditions. Out of 12 genotypes MS 1826 and MS 4684 had an average response and appeared unpredictable stability. However, among the genotypes studied, TNPsu 141 possessed low yield and perform better in sub -optimum environments which are inferred by less than unit regression.


2020 ◽  
Vol 1 (1) ◽  
pp. 13-19

Wheat considered to be the most important among all cereal crops, is grown across various agro-ecological zones around the globe. It is the main staple food playing a prominent role in the economy of the country as well as in the cropping system. The present study was conducted to estimate genotypic correlations among morphological traits and yield using 50 accessions of diploid wheat including 2 parents and 48 RILs at F7:8 stage to determine direct as well as indirect effects. The results presented here showed that generally the coefficients of genotypical correlation (rg) depicted higher values in comparison to the coefficients of phenotypic correlation (rp). Among the morphological traits contributing to the grain yield, genotypic as well as phenotypic coefficients of correlation have been evaluated. All the traits displayed positive correlation with each other except emergence percentage (EP) that depicted negative interaction with booting time (BT), flowering time (FT) and heading time (HT) phenotypically. Highest estimates of direct effect i.e., 2.1217 on grain yield have been counted for booting time however, maximum indirect effect counted on grain yield was for heading time via booting time. Therefore, booting time can be successfully employed as an effective trait in the breeding programs focused on increasing wheat yield.


2019 ◽  
Vol 11 (3) ◽  
pp. 414-421
Author(s):  
Lawrence FAYEUN ◽  
Sayo SESAY

Superiority of hybrid maize cannot be overemphasized. Different types of hybrids are developed by plant breeders to improve productivity and multi-locational evaluation of these hybrids prior to release is necessary to select the best. The objectives of this study were to identify maize hybrids with superior agronomic potentials and compare the performance of top-cross and three-way cross hybrid maize varieties for grain yield and related traits under rain-fed condition in three different locations (Abeokuta, Ibadan and Akure) of Southwest Nigeria. The study consisted of ten hybrids each of top-cross and three-way cross hybrid varieties, tested with two checks. At each location, the experiment was laid out in randomised complete block design with three replications. The results showed that effects of locations, genotypes and genotype x location interactions were highly significant (p<0.01) for all the traits evaluated. Significant differences were also revealed between the top-cross and three-way cross hybrids for all the traits evaluated except days to 50% tasseling, ear diameter and 100-grain weight. The top-cross hybrids were superior over the three-way cross hybrids for grain yield by 5.25%. The hybrids ‘M0926-7’, ‘M0926-8’, ‘M1026-11’, ‘M1026-3’, ‘M1226-2’ (top-cross hybrids), ‘M1124-24’, ‘M1124-27’, ‘M1124-31’, ‘M1227-6’ and ‘M1227-7’ (three-way cross hybrids) showed highest stable yields across the three locations.  Hybrids ‘M0926-7’ (top-cross hybrid) and ‘M1124-24’ (three-way cross hybrid) that expressed early flowering with higher grain yield are recommended for drought stress prone areas because of their abilities to tolerate drought through escape.


2021 ◽  
Vol 5 ◽  
Author(s):  
Aloysius Beah ◽  
Alpha Yaya Kamara ◽  
Jibrin Mohamed Jibrin ◽  
Folorunso Mathew Akinseye ◽  
Abdullahi Ibrahim Tofa ◽  
...  

The Agricultural Production Systems Simulator (APSIM) model was calibrated and validated and used to identify the optimum planting windows for two contrasting maize varieties for three agro-ecologies in the Nigeria savannas. The model was run for 11 planting windows starting from June 1 and repeated every 7 days until 16 August using long-term historical weather data from the 7 selected sites representing three agro-ecological zones (AEZs). The evaluation with the experimental data showed that the model performance was reasonable and accurately predict crop phenology, total dry matter (TDM) and grain yield for both maize varieties. The seasonal planting date analysis showed that optimum planting windows for 2009EVDT and IWDC2SynF2 depend on the variety, agro-ecozones and sites. Planting from June 15 to 28 simulated the highest mean grain yield for both varieties in all the agro-ecologies. In the Southern Guinea savanna (SGS) where the length of growing season is 180–210 days, the best planting window was June 8–July 19 for 2009EVDT and June 8–July 26 for IWDC2SynF2 in Abuja. The planting window that gives attainable yield at Yelwa, is June 15–July 5 for 2009EVDT and June 8–28 for IWDC2SynF2. In the Northern Guinea savannah (NGS) where the length of growing season is 150–180 days, the optimum planting window is June 15–July 19 for both varieties at Zaria and June 8–July 19 for 2009EVDT and June 8–August 2 for IWDC2SynF2 at Sabon Gari. In the Sudan savannah (SS) where the growing season is 90–120 days, planting of 2009EVDT can be delayed up to the third week of July. For the medium-maturing variety, IWDC2SynF2, planting should be done by the first week of July. Though Yelwa is in the SGS, lower yields and narrower sowing windows were simulated for both varieties than for those of the other locations. This is probably due to the poor soil fertility in this location.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Li-qing Wang ◽  
Xiao-Fang Yu ◽  
Ju-Lin Gao ◽  
Da-Ling Ma ◽  
Liang Li ◽  
...  

AbstractGrain filling is the key stage for achieving high grain yield. Subsoiling tillage, as an effective conservation tillage, has been widely used in the maize planting region of China. This study was conducted to explore the effects of subsoiling on the grain filling characteristics of maize varieties of different eras. Five typical maize varieties from different eras (1970s, 1980s, 1990s, 2000s and 2010s) were used as experimental materials with two tillage modalities (rotation tillage and subsoiling tillage). The characteristic parameters (Tmax: the time when the maximum grouting rate was reached, Wmax: the grain weight at the maximum filling rate, Rmax: the maximum grouting rate, P: the active grouting stage, Gmean: the average grouting rate; A: the ultimate growth mass) and rate parameters (T1: the grain filling duration of the gradually increasing stage, V1: the average grain filling rate of the gradually increasing stage, T2: he grain filling duration of the rapidly increasing stage, V2: the average grain filling rate of the rapidly increasing stage, T3: the grain filling duration of the slowly increasing stage, V3: the average grain filling rate of the slowly increasing stage) of grain filling of two tillage modalities were analyzed and compared. The results showed that the filling parameters closely correlated with the 100-kernel weight were significantly different among varieties from different eras, and the grain filling parameters of the 2010s variety were better than those of the other varieties, the P and Tmax prolonged by 4.06–19.25%, 5.88–27.53% respectively, the Rmax and Gmean improved by 5.68–14.81%, 4.76–12.82% and the Wmax increased by 10.14–32.58%. Moreover, the 2010s variety helped the V2 and V3 increase by 6.49–13.89%, 4.55–15.00%. In compared with rotation tillage, the grain yield of maize varieties from different eras increased by 4.28–7.15% under the subsoiling condition, while the 100-kernel weight increased by 3.53–5.06%. Under the same contrast conditions, subsoiling improved the Rmax, Wmax and Gmean by 1.23–4.86%, 4.01–5.96%, 0.25–2.50% respectively, delayed the Tmax by 4.04–5.80% and extended the P by 1.19–4.03%. These differences were major reasons for the significant increases in 100-kernel dry weight under the subsoiling condition. Moreover, subsoiling enhanced the V2 and V3 by 0.70–4.29%, 0.00–2.44%. The duration of each filling stage and filling rate of maize varieties from different eras showed different responses to subsoiling. Under the subsoiling condition, the average filling rate of the 1970–2010s varieties were improved by 1.18%, 0.34%, 0.57%, 1.57% and 2.69%. In the rapidly increasing period, the grain filling rate parameters of the 2010s variety were more sensitive to subsoiling than those of the other varieties. The rapidly increasing and slowly increasing period are the key period of grain filling. Since the 2010s variety and subsoiling all improve the grain filling rate parameters of two periods, we suggest that should select the variety with higher grain filling rate in the rapidly increasing and slowly increasing period, and combine subsoiling measures to improve the grain filling characteristic parameters of maize in production, so as to achieve the purpose of increasing 100 grain weight and yield.


1970 ◽  
pp. 33-36
Author(s):  
Faizan Mahmood, Hidayat- Ur-Rahman, Nazir Ahmad ◽  
Fahim-ul- Haq ◽  
Samrin Gul, Quaid Hussain ◽  
Ammara Khalid ◽  
Touheed Iqbal ◽  
...  

This study evaluated the performance of 64 half sib families (HSF) derived from “Azam” variety of maize using partially balanced lattice square design with two replications. Data were recorded on grain yield and other agronomic traits. Observations showed difference in half-sib families for studied traits. Among the 64 half-sib families, minimum days to 50% tasseling (51 days) were observed for HS-49 while maximum (57 days) for HS-63. Minimum days to 50% silking (56 days) were counted for HS-6 while maximum (63 days) for HS-23. Minimum days to 50% anthesis (55 days) were counted for HS-1 and HS-6 while maximum (62 days) for HS-23. Similarly, minimum ASI (-2 days) were observed in HS-1, HS-15, HS-16, HS-28 and HS-63 while maximum (2 days) in HS-48. Minimum (60 cm) ear height was recorded for HS-11 and maximum (93.5 cm) for HS-28. Minimum fresh ear weight (1.3 kg) was weighted for HS-17 while maximum (3.2 kg) for HS-21. Grain moisture was recorded minimum (19.35 %) for HS-19 and maximum (31.25%) for HS-2. HS-42 showed minimum (28 g) 100 kernel weight while HS-5 showed maximum (47 g). Grain yield was minimum (2323 kg ha-1) for HS-17 and maximum (5742 kg ha-1) for HS-21. Maximum heritability estimate (0.92) was recorded for fresh ear weight, while minimum (0.41) was observed for ear height.


Agronomy ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 76
Author(s):  
Aloysius Beah ◽  
Alpha Y. Kamara ◽  
Jibrin M. Jibrin ◽  
Folorunso M. Akinseye ◽  
Abdullahi I. Tofa ◽  
...  

This paper assessed the application of the Agricultural Production Systems sIMulator (APSIM)–maize module as a decision support tool for optimizing nitrogen application to determine yield and net return of maize production under current agricultural practices in the Nigeria savannas. The model was calibrated for two maize varieties using data from field experiments conducted under optimum conditions in three locations during the 2017 and 2018 cropping seasons. The model was evaluated using an independent dataset from an experiment conducted under different nitrogen (N) levels in two locations within Southern and Northern Guinea savannas. The results show that model accurately predicted days to 50% anthesis and physiological maturity, leaf area index (LAI), grain yield and total dry matter (TDM) of both varieties with low RMSE and RMSEn (%) values within the range of acceptable statistics indices. Based on 31-year seasonal simulation, optimum mean grain yield of 3941 kg ha−1 for Abuja, and 4549 for Kano was simulated at N rate of 120 kg ha–1 for the early maturing variety 2009EVDT. Meanwhile in Zaria, optimum mean yield of 4173 kg ha–1 was simulated at N rate of 90 kg ha−1. For the intermediate maturing variety, IWDC2SYNF2 mean optimum yields of 5152, 5462, and 4849 kg ha−1, were simulated at N application of 120 kg ha−1 for all the locations. The probability of exceeding attainable mean grain yield of 3000 and 4000 kg ha−1 for 2009EVDT and IWDC2SYNF2, respectively would be expected in 95% of the years with application of 90 kg N ha−1 across the three sites. Following the profitability scenarios analysis, the realistic net incomes of US$ 536 ha–1 for Abuja, and US$ 657 ha−1 for Zaria were estimated at N rate of 90 kg ha−1 and at Kano site, realistic net income of US$ 720 ha–1was estimated at N rate of 120 kg ha−1 for 2009EVDT.For IWDC2SYNF2, realistic net incomes of US$ 870, 974, and 818 ha−1 were estimated at N application of 120 kg ha−1 for Abuja, Zaria, and Kano respectively. The result of this study suggests that 90 kg N ha−1 can be recommended for 2009EVDT and 120 kg N ha–1 for IWDC2SYNF2 in Abuja and Zaria while in Kano, 120 kg N ha−1 should be applied to both varieties to attain optimum yield and profit.


Genetics ◽  
1997 ◽  
Vol 145 (2) ◽  
pp. 453-465 ◽  
Author(s):  
Zhikang Li ◽  
Shannon R M Pinson ◽  
William D Park ◽  
Andrew H Paterson ◽  
James W Stansel

The genetic basis for three grain yield components of rice, 1000 kernel weight (KW), grain number per panicle (GN), and grain weight per panicle (GWP), was investigated using restriction fragment length polymorphism markers and F4 progeny testing from a cross between rice subspecies japonica (cultivar Lemont from USA) and indica (cv. Teqing from China). Following identification of 19 QTL affecting these traits, we investigated the role of epistasis in genetic control of these phenotypes. Among 63 markers distributed throughout the genome that appeared to be involved in 79 highly significant (P &lt; 0.001) interactions, most (46 or 73%) did not appear to have “main” effects on the relevant traits, but influenced the trait(s) predominantly through interactions. These results indicate that epistasis is an important genetic basis for complex traits such as yield components, especially traits of low heritability such as GN and GWP. The identification of epistatic loci is an important step toward resolution of discrepancies between quantitative trait loci mapping and classical genetic dogma, contributes to better understanding of the persistence of quantitative genetic variation in populations, and impels reconsideration of optimal mapping methodology and marker-assisted breeding strategies for improvement of complex traits.


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