Environmental Coefficients Of Variation Research Articles

Correlation and Pathway Analysis and their Applications to Improve Yield in Bread Wheat Under Humic Acid Conditions

This study aimed to know the relationship between growth traits and yield components with yield by studying some statistical and genetic parameters in addition to correlation and path analyses . The study included fifteen types of bread wheat (Sham 8, Aba 99, Kraita, Al_ Ezz, Aba 95, Mexibak, Sham 6, Abu Ghraib 3, Al-Fath, Intisar, Latifa, Tamouz3, Bohouth 22, and Al_Rasheed) under the influence of three levels of humic acid (0, 20 and 40 kg.h−1) using the Randomized complete block design to the arrangement of split plots with three replicates and characteristics, the number of days to heading ofspikes, the area of the flag leaf, plant height, number of active tillers, number of grains of the spike, 1000 grains weight and the total yield. The most important results were summarized as: The presence of high genetic variance compared to environmental variance, which was reflected in the high value of heritability in the broad sense, and that the coefficient of environmental variation was low compared to the coefficient of genetic and phenotypic variation, which was average, and that the expected genetic improvement as a percentage was average for all studied traits except number of days to heading trait varying levels of humic acid. We conclude from this that the third level can be considered a good and suitable environment through direct selection of the two characteristics number grains per spike and grains thousand weight to improve the yield in the future.

Exploring the Phenotypic and Genetic Variabilities in Yield and Yield-Related Traits of the Diallel-Crossed F5 Population of Aus Rice.

Rice (Oryza sativa) is a major crop and a main food for a major part of the global population. Rice species have derived from divergent agro-climatic regions, and thus, the local germplasm has a large genetic diversity. This study investigated the relationship between phenotypic and genetic variabilities of yield and yield-associated traits in Aus rice to identify short-duration, high-yielding genotypes. Targeting this issue, a field experiment was carried out to evaluate the performance of 51 Aus rice genotypes, including 50 accessions in F5 generation and one short-duration check variety BINAdhan-19. The genotypes exhibited a large and significant variation in yield and its associated traits, as evidenced by a wide range of their coefficient of variance. The investigated traits, including days to maturity (DM), plant height (PH), panicle length (PL) and 1000-grain weight (TW) exhibited a greater genotypic coefficient of variation than the environmental coefficient of variation. In addition, the high broad-sense heritability of DM, PH, PL and TW traits suggests that the genetic factors significantly influence the observed variations in these traits among the F5 Aus rice accessions. This study also revealed that the grain yield per hill (GY) displayed a significant positive correlation with PL, number of filled grains per panicle (FG) and TW at both genotype and phenotype levels. According to the hierarchical and K-means cluster analyses, the accessions BU-R-ACC-02, BU-R-ACC-08 and R2-36-3-1-1 have shorter DM and relatively higher GY than other Aus rice accessions. These three accessions could be employed in the ongoing and future breeding programs for the improvement of short-duration and high-yielding rice cultivars.

Genetic parameters in Conilon coffee in an irrigated systema in cerrado

The production of robusta coffee plays a significant role in the Brazilian economy and the agriculture of various Brazilian states due to its adaptability and high yield. The characterization of genetic resources and the estimation of genetic parameters of populations contribute to breeding programs in the development of genotypes adapted to the irrigated cultivation system in the Cerrado, for the target traits. The objective was to characterize the available genetic resources of robusta coffee in elite collections and estimate genetic parameters related to agronomic traits in an irrigated cultivation system in the Cerrado. Productivity, processed coffee yield, plant height, and the number of vegetative and reproductive nodes in plagiotropic branches were evaluated for 35 robusta coffee genotypes over two consecutive years, using a split-plot design with genotypes as the main plots, replicated three times, and years as the subplots. The data were subjected to analysis of variance, and genetic parameters were estimated. Significant genotype effects were observed only for plant height. Significant effects were observed for the year factor and genotype x year interaction for all traits. High heritability values and a genotypic coefficient of variation greater than the environmental coefficient of variation were obtained for plant height. Negative genotypic variances were obtained for the other traits. Favorable conditions exist for selecting smaller stature genotypes based on plant height, associated with productivity.

Variability and heterosis of seed vigour traits in hybrid rice (Oryza sativa L.)

The cultivars with high seed vigor are desirable for farmers to establish optimum plant stand under sub-optimal field conditions. The basic physiological processes are required to understand the hybrid vigor phenomenon, particularly for seed vigor and associated characteristics. Limited information on seed vigor in rice hybrids and their parental lines in relation to physical, physiological and biochemical characters are available. Three released rice hybrids and their respective female (A), maintainer (B) and restorer/male (R) lines were assessed for physical, physiological and biochemical traits related to seed vigor. Significant differences were found among the three rice hybrids and its parental lines for 100 seed weight, weight of kernel, husk, endosperm and embryo. Germination percentage, seed vigor index-I and seed vigor index-II were highly significant among female and male lines and hybrids in fresh seed because of potential heterosis in hybrids. Higher activity of reactive oxygen species (ROS) scavenging enzymes such as catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) in hybrids was estimated as compared to that of their parental lines. The study showed the presence of the genetic variability, phenotypic, genotypic and environmental coefficient of variation, heritability, genetic advance and heterosis for seed vigor traits in three rice hybrids and its parental lines. A favorable combination of seed vigor traits would be useful to develop desired variety and hybrids with superior seed vigour for realizing higher grain yield and better adaptability in any condition.

Higher stability of oat, barley and wheat accessions in their 1000 grain weight is not associated with a smaller grain size

Background. It is important and relevant to know whether the selection among cultivars for increased stability in the weight of 1000 grains involves a significant change in grain size. The aim of the study was to analyze the relationship between the 1000 grain weight in oat, barley and wheat accessions, on the one hand, and their adaptability indicators for this trait, on the other. Material and methods. The studied material included 10 cultivars of oat, 12 of barley, and 11 of wheat from the VIR collection. Plants were grown in 2021 at five different sites over Eastern Siberia (Krasnoyarsk Territory, and the Republic of Khakassia and Tyva). After harvesting, the weight of 1000 grains was measured for each cultivar. The coefficient of environmental variation (Cv), stress tolerance index (d), homeostasis parameter (Hom), stability level index (CSL), and breeding value index (Cs) were determined to assess the cultivars for the analyzed character. Results. Oat cultivars exhibited significantly lower plasticity and higher stability in their 1000 grain weight. The best adaptability characteristics were recorded for oat cvs. ‘Argument’ and ‘Kross’, barley cvs. ‘Krasnoyarsky 91’ and ‘Biom’, and wheat cvs. ‘Novosibirskaya 49’ and ‘Novosibirskaya 75’. Cvs. ‘Kross’ and ‘Argument’ (oat). and ‘Biom’ (barley) had the largest grain size and maximum values of the character’s stability parameters. Correlations of oat and wheat grain size with both plasticity indices were negative, and positive with all stability parameters, being significant for CSL and Cs. In the case of barley cultivars, the correlation between the weight of 1000 grains and the plasticity index was negative and statistically significant. Conclusion. The results demonstrate that when selecting oat, barley and wheat for increased stability of their 1000 grain weight, the grain size will not decrease. Moreover, it may have a tendency to increase.

Desempenho de cultivares de pimenta, baseado em caracteres de frutos, para consumo in natura

ABSTRACT Different studies report that pepper fruit cuticle and pericarp thickness vary among marked cultivars and these variations likely influence many fruit quality traits, especially water loss rates. Thus, the objectives of this work was to evaluate the fresh market performance of pepper cultivars based on fruit traits, and indicate the cultivars of Capsicum spp. with less probability of post harvest water loss. Pepper fruits, belonging to C. chinense, C. frutescens and C. baccatum species, were collected in an experimental area at Bonfim’s settlement, Alagoinha, Paraíba, Brazil. After harvest, fruits were taken to the laboratory of biotechnology at Centro de Ciências Agrárias of the Universidade Federal da Paraíba. Fruits were characterized according to pericarp thickness, fruit weight, and fruit length, larger and smaller fruit diameter. The experimental design was completely randomized with eight treatments and four repetitions. Analysis of variance, mean test, heritability, and ratio of coefficient of genetic variation by coefficient of environmental variation, genotypic and environmental correlation, and Tocher’s grouping method were performed. The cultivar habanero vermelha had better performance for fruit weight and larger and smaller fruit diameter. On the other hand ‘dedo de moça’ presented the longest fruits and major pericarp thickness. These two cultivars also belonged to different groups based on Tocher’s method. The genetic correlation between pericarp thickness and fruit weight was high (0.70) and highly significant. Fruit wall thickness also presented highly significant genotypic correlation with larger fruit diameter (0.93) and small fruit diameter. (0.93). Those finds indicate that indirect selection for pericarp thickness could be done based on larger fruit diameter. These correlations are trustworthy and important due to the high heritability values presented for these traits. Some authors suggest selecting fruits with higher cuticle thickness and fruit width values due to lower water loss. Thus, we suggest that small farmers cultivate ‘habanero vermelha’ and ‘dedo de moça’ in order to produce fruits with extended shelf life.

Genetic Variability and Character Association Study for Yield Enhancement in Bread Wheat (Triticum aestivum L.)

This study was conducted to examine 20 bread wheat genotypes with two checks to investigate genetic parameters, correlations and genetic diversity. This experiment was done in main experimental station of Agricultural Research Farm, Rama University (U.P), Mandhana, Kanpur during Rabi Season, 2020-21 in Randomized Block Design (RBD) with three replications. Analysis of variance showed a very significant difference between the 20 bread wheats of the 11 characters investigated. Genotype HPAN111 showed high grain yields per plant during the control period based on average production. Genotypic coefficient of variation (GCV) was recorded highest for Biological yield per plant (15.073%). Phenotypic Coefficient of Variation (PCV) was recorded highest for Biological yield per plant (16.316%). Environmental coefficient of variation (ECV) was recorded highest for Effective tiller per plant (13.591%). High heritability was observed for most of the traits and it was noted highest for Biological yield per plant (85.4%). Genetic advancement was recorded highest for Biological yield per plant (643.733%). The high Genetic advance as per cent of mean was recorded for Biological yield per plant (28.687%). Grain yield per plant shows Significant Positive Correlation with Biological yield per plant (0.8803**) at genotypic and phenotypic level.

Selection criteria for tomato lines with defined growth habit

Introduction: The selection of genotypes with determinate growth habit in tomato should contemplate adequate selection criteria to increase the efficiency of the breeding program. Objective: The objective of this work was to estimate selection criteria for “chonto” type tomato lines with determined growth habit. Materials and methods: This work was carried out at the Universidad Nacional de Colombia (Palmira Campus), in 2016, with seven lines with determinate growth habit and a control with indeterminate growth. Heritability in a broad sense (h2 g), coefficient of environmental variation, coefficient of genetic variation, selection efficiency and genetic gain were determined in parameters of morphological, phonological, fruit quality, fruit shape and production, using the RELM/BLUP procedure of the SELEGEN software. Results: There were three ranges of h2 g, the first with values of h2 g greater than 0.76, the second between 0.53 and 0.38, and the third with a value less than 0.38. The highest values of h2 g were for final plant height with 0.92, plant height at harvest with 0.88, yield per plant with 0.83, days to flowering with 0.83, number of fruits per plant with 0.82, and days to harvest with 0.82. For genetic gain it was found that the control had the highest values for final plant height, plant height at harvest, internode length, days to harvest, harvest duration, soluble solids content, number of fruits per plant, fruit weight and yield per plant; however, in some parameters such as height and phenology for selection by determined growth habit, the lowest values were better. Conclusion: There was evidence of genetic parameters that could be considered as selection criteria for “chonto” type tomato lines with determinate growth habit.

Genetic Variability in Growth Characteristics among Different Clones of Eucalyptus tereticornis Sm.

The present investigation was carried out at the College of Forestry, Odisha University of Agriculture and Technology, Bhubaneswar, Odisha, India during August, 2018 to June, 2019 to study the genetic variability in growth characteristics among different clones of Eucalyptus tereticornis. Different clones of Eucalyptus tereticornis Sm. were planted in RCBD, with 4 replications revealed significant variations among all eight treatments (clones) with respect to 9 different characters. Based on the mean performance, treatment-1 (clone-526) showed maximum value for characters like biomass (1124.17), plant height (247.9 cm), collar diameter (23.25 mm), and a number of leaves plant-1 (463.25 number). Similarly, the maximum value was observed in treatment-8 (clone-136) for traits like leaf area (42.70 cm2), leaf length (15 cm), and leaf width (5.75 cm). The highest leaf length to leaf width ratio (3.57) and lowest number of branches plant-1 (18.75 number) were found in treatment-2 (clone-288). All characters had exhibited higher genotypic variance than an environmental variance. Similarly, the genetic coefficient of variation in the case of all variables was also found greater than an environmental coefficient of variation. Heritability was found maximum in plant height (87.35%) and all other characters also showed high heritability. Genetic advance as % of mean was found maximum in biomass (71.15%). Based on the overall mean performance of growth characters, Treatment-1 (Clone-526) was found as a superior clone with respect to the most important character biomass for the test locality. High GCV, heritability, and GAM value for biomass indicated that the character would respond to selection for the improvement program.

Genetic variability parameters of maize (Zea mays L.) mutant irradiated gamma-ray

Mutation induction often used to increase genetic variability in plant breeding for further proceed. Thirty inbred lines of maize mutants (M1) of were evaluated in a randomized complete block design experiment with three replications for morphology and agronomy of genetic variability parameters. Data were collected on days to anthesis and silking, anthesis-silking interval (ASI), plant height, leaves number, days to maturity, ear number, grain yield, grains number, weight of 100-grain. Mean values were used to determine characters’ phenotypic and genotypic variances, phenotypic, genotypic and environmental coefficients of variation. Moderate heritability estimates were observed for most traits. Otherwise based on genotypic coefficient of variance, for most traits had low genetic variability but generally high genetic variability was observed for most traits based on standard deviation of genotypic variance. Grain yield as important trait had moderate genetic variability based on heritability estimates, high based on genotypic coefficient of variance and standard deviation of genotypic variance. Hence provides better opportunities for selecting plant material regarding these traits.

Morphological diversity, phenotypic and genotypic variance and heritability estimates in Moringa oleifera Lam.: a less used vegetable with substantial nutritional value

Moringa oleifera Lam. (common name: drum stick, horseradish tree) belongs to the monogeneric family, Moringaceae. Immature pods, fresh leaves and flowers of M. oleifera are used for culinary purposes. The leaves and young pods are a rich source of minerals and vitamins. In the present study, 23 genotypes of drumstick, which were selected based on superiority of yield/tree from 120 genotypes surveyed in South India were subjected to analysis morphology, yield and quality attributes and found they are substantially varying thus necessitate further analysis. Diversity analysis based on the coefficient of variation (CV), genotypic coefficient of variation (GCV), environmental coefficient of variation (ECV), phenotypic coefficient of variation (PCV) and heritability were determined. Quantitative fruit traits such as fruit length (30.56–127.57 cm), fruit weight (72.22–163.27 g), fruit breadth (3–8 cm), number of fruits/tree (NF/T) (320–1000), and number of seeds/fruit (NS/F) (11–29) varied among the genotypes. Correlation studies revealed that the fruit yield had a significant, positive correlation with the number of fruits per tree, length of fruit and single fruit weight. The estimate of PCV was slightly higher than the GCV for all characters studied, indicating that the apparent variation is not only genetic but also influenced by the growing environment in the expression of the traits. Heritability was greater than 90% for all characters studied. The overall analysis outcome of the study emphasizes that selection of high yielding genotypes should give due weightage to the number of fruits per tree and single fruit weight.

Study of repeatability and phenotypical stabilization in kale using frequentist, Bayesian and bootstrap resampling approaches

The aim of this study was to obtain information for the genetic improvement of kale through repeatability and phenotypic stabilization studies and to compare methodologies that represent the reliability of the estimated parameters. Thirty-three half-sib progenies were evaluated in a randomized block design with three replicates and six plants per plot. Eight harvests were evaluated in terms of the yield of fresh leaves, number of shoots, number of leaves and average mass of leaves. Then, a phenotypic repeatability and stabilization study was performed, estimating the genetic parameters σ2a, σ²g, σ²e, and the coefficient of environmental variation and repeatability using the frequentist and Bayesian methodologies. To evaluate the reliability of these estimates, intervals were obtained using the frequentist, Bayesian and bootstrap methods. It was verified that the reliable selection of progenies of half-sib of kale can be achieved in four harvests that were realized between 95 and 170 days after planting. It was observed that the frequentist and Bayesian methodologies are better suited to obtain reliable estimates of the genetic parameters evaluated, as the last one provided smaller amplitudes for the obtained intervals. The bootstrap methodologies are not recommended for phenotypic repeatability and stabilization studies in kale.

Genetic variability, heritability and correlation among soybean [<i>Glycine max</i>. (L.) Merrill] varieties

The study was conducted at Teaching and Research Farm, Faculty of Agriculture, Bayero University, Kano (Lat 11059`N, Long 8025`E and 466m above sea level), during 2016 rainy season, to determine the variability, heritability and correlation among the soybean varieties. The treatments consist of eight soybean varieties, laid out in Randomized Complete Block Design (RCBD) and replicated four times; varieties were evaluated for fifteen characters to determine variability, estimate heritability and correlation. Analysis of variance revealed significant difference (P>0.01<0.05) with respect to four characters and highly significant (P≤0.01) four seven characters. The results indicated the presence of substantial variability among the varieties. GCV, PCV, ECV and heritability estimates ranges from 0.000039-169.18, 0.000066-187.55, 0.000053-122.28 and 0-100% respectively, the high Genotypic Coefficient of Variation (GCV), Phenotypic Coefficient of Variation (PCV) and Environmental Coefficient of Variation (ECV) observed in this study indicated the existence of variability and selection can be done. Whereas high estimate of broad Sense heritability for the tested parameters indicated that these characters were highly heritable and selection can be imposed. Significant phenotypic correlation for GWha and FWha with FWP respectively revealed that, these characters were primarily influenced by their direct contribution to higher yield. It is therefore recommended for an effective selection of those characters could be adopted for cultivar improvement and hybridization program and more research is needed to validate the findings.Keywords: Genetic, Heritability , Soybean, Variability

Genetic Variability, Correlation and Path Coefficient Analysis in Advanced Generation of Brassica napus L.

The present study was conducted involving 62 F3 genotypes of Brassica napus L. at the experimental farm of Sher-e-Bangla Agricultural University, Dhaka, Bangladesh to ponder the genetic variability, phenotypic, genotypic and environmental coefficient of variation, heritability and genetic advance, correlation, path coefficient and genetic diversity analysis in a randomized complete block design (RCBD) with sixty-two genotypes (treatments) with three replications during November 2014 to February 2015. The investigations aimed to select the best segregating genotypes for the yield improvement of Brussica napus (rapeseed). Analysis of variance indicated that the genotypes were found significantly different for all the characters considered. The relative phenotypic coefficient of variation (PCV) was higher than the genotypic coefficient of variation (GCV) for all the traits investigated. The high GCV value was observed for the number of siliqua per plant (NSP), plant height (PH), silique length (SL), number of seed per silique (NSS) and seed yield per plant (SYP) indicated high broad sense heritability. The significant positive correlation with seed yield per plant (SYP) was found in plant height (PH) (0.368**), the number of primary branches per plant (NPB) (0.332**), number of secondary branches per plant (NSB) (0.382**), number of silique per plant (NSP) (0.549**), and siliqua length (SL) (0.037**). The results of path coefficient analysis uncovered that plant height (PH) (0.582), days to 50% flowering (50F) (0.390), days to maturity (DM) (0.575), number of primary branches per plant (NPB) (0.678), number of secondary branches per plant (NSB) (0.182),and thousand seed weight (TSW) (0.289) had a positive direct impact on seed yield per plant (SYP) and thus it was concluded that these traits could be exploited for the enhancement of yield potential of rapeseed. This study showed that based on the agronomic performance execution, genotypes G8, G14, G19, G21, G47, and G55 might be proposed for future hybridization program in Bangladesh and this could help rapeseed breeders to upgrade their breeding activities.

English

The present study consists of 14 sorghum genotypes evaluated at Bako, Jimma and Mechara research centers to study genetic variability and interrelationships of traits with grain yield. The experiment was conducted by using randomized complete block design (RCBD) with three replications during 2014 and 2015 main rainy season. Data on important agronomic traits were collected. The combined analysis of variance (ANOVA) across years and locations showed highly significant differences among genotypes for all traits, indicating the presence of sufficient variability among the genotypes. Environmental coefficients of variation (ECV), genotypic coefficients of variation (GCV) and Phenotypic coefficient of variation (PCV) ranges of the study are days to 50% maturity (DM, 0.49) to number of seeds per panicle (NSPP, 6.11); DM (0.31) to PAS (16.99) and DM (1.12) to GY (20.86) in the same order. High h2BS values were observed in hundred seed weight (HSW, 76%), DS (70%), plant height (PH, 65%) and PAS (63). High value of genetic advance as a percentage of mean (GA% µ) was recorded by PAS (27.42%), PH (26.29%) and DS (20.65%) and moderate amount of GA%µ was recorded by HSW (11.78%) and HW (11.08%). High h2BS coupled with high to moderate GA%µ was reported for PH (65 and 26.29%); HSW (76 and 11.78%); PAS (63 and 27.42%) and DS (70 and 20.65%) indicating PH and HSW are controlled by additive gene action. GY had strong positive genotypic association with HW (0.99) followed by NSPP (0.96). These results suggested that any positive increase in such traits will increase the grain yield. The genotypic path analysis also showed that head weight per plot (HW, 1.96) and PH (0.55), had high and very high positive direct effect, respectively on GY indicating that these traits are the most important yield component traits. Hence, due consideration should be given to these traits while selecting promising lines. Key words: Correlation coefficient, genetic advance, heritability, path coefficient, sorghum. &nbsp

Bayesian approach, traditional method, and mixed models for multienvironment trials of soybean

Abstract: The objective of this work was to compare the Bayesian approach and the frequentist methods to estimate means and genetic parameters in soybean multienvironment trials. Fifty-one soybean lines and four controls were evaluated in a randomized complete block design, in six environments, with three replicates, and soybean grain yield was determined. The half-normal prior and uniform distributions were used in combination with parameters obtained from data of 18 genotypes collected in previous and related experiments. The genotypic values of the genotypes of high- and low-grain yield, clustered by the Bayesian approach, differed from the means obtained by the frequentist inference. Soybean assessed through the Bayesian approach showed genetic parameter values of the mixed model (REML/Blup) close to those of the following variables: mean heritability (h2mg), accuracy of genotype selection (Acgen), coefficient of genetic variation (CVgi%), and coefficient of environmental variation (CVe%). Therefore, the mixed model methodology and the Bayesian approach lead to similar results for genetic parameters in multienvironment trials.

Genetic variability in morphological characters among Fig tree accessions Fig genetic conservation

Fig is among the twenty main fruits exported by Brazil, which is the eighth largest producer of fig in natura in the world. The characterization of active germplasm banks (AGBs) of fig has thus become an important line of research, as it is necessary to gather information from this to carry out adequate management projects. The objective of this study was to characterize the morphologies of 42 fig tree accessions, so that the quality and genetic potential of different accessions of the species could be recognized based on the characteristics of the vegetative parts of the plants. Estimates of variance components were obtained for each variable evaluated using the restricted maximum likelihood/best linear unbiased prediction procedure, available in the genetic-statistical software SELEGEN. The majority of the characters analyzed had a genotypic coefficient of variation lower than the environmental coefficient of variation. However, all characters had non-zero heritability, showing that there is genetic variability among the accessions related to the characters tested. The population studied has medium to high genetic variability, indicating that it is possible to identify the materials based on morphological descriptors, among which the number of lobes of the leaves appeared to be the most promising.

Study on genetic variability, heritability and genetic advance in Soybean[Glycine max (L.) Merrill

Soybean, an important legume crop, serves as a good source of protein and oil with tremendous ability to fix atmospheric nitrogen for soil improvement. To study the genetic variability, genotypic, phenotypic and environmental coefficient of variation, broad sense heritability and genetic advance in soybean, a field experiment was conducted during Kharif 2013. The experiment, laid out in a randomized block design (RBD) with three replications, comprised of 24 genotypes and observations on 9 traits of soybean were recorded. In this experiment, analysis of variance indicated that significant variation were present among the different genotypes of the soybean for all the traits under study. The highest genotypic (GCV) and phonotypic coefficient of variation (PCV) were exhibited by the test weight, number of pods per plant, harvest index and plant height. The PCV was found higher than GCV which indicates the important role of environment in the expression of the characters. High heritability and high genetic advance were observed in the test weight, number of pods per plant, harvest index and plant height. The combination of the high heritability and high genetic advance provide the clear image of the trait in the selection process for crop improvement programme.

Performance of sweet potato clones for starch and ethanol in three regions of the state of Sergipe, Brazil

Sweet potato (Ipomoea batatas L.) is a species that belongs to the family Convolvulaceae, and is originated from Central America and South America. As the growing conditions have great influence on the crop, the determination of harvesting time may vary with the cultivar, the growing region, or with the type of consumption (in natura or industrial). The aim of this work was to evaluate the performance of Ipomoea batatas L. clones, cultivated in three regions in the state of Sergipe, for starch and ethanol production. Thirty-one sweet potato clones grown in three municipalities of the state of Sergipe were tested in a randomized block design. The following variables were analyzed: root dry matter content (RDMC), root starch content (SC), starch yield (SY), ethanol yield (EY), and ethanol yield per ton of root (EYR). EY values ranged from 5910.39 to 8516.12 L ha-1; from 5141.85 to 6937.63 L ha-1; and from 5829.62 to 8211.77 L ha-1 in the municipalities of Sao Cristovao, Malhador, and Caninde de Sao Francisco, respectively, for clones IPB-075 and IPB-087 and cultivar Palmas. Estimates of heritability (h2) were above 50%. The values of the ratio between the coefficient of genetic variation (CVg) and the coefficient of environmental variation (CVe) for RDMC, SC, and EYR were high.

Genetic variability, character association and path analysis in maize (Zea mays L.)

Twenty-two maize hybrids were evaluated to find out their variability, character association and path coefficient of grain yield and its component characters. Significant differences were found among the genotypes for the characters studied. Ear length and grain yield (t/ha) had moderate genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV), but the had the low environmental co-efficient of variation (ECV). The heritability for all the characters was high. The characters viz. plant height, ear height and 1000-grain weight, showed high heritability along with high genetic advance. Ear length, ear diameter and kernel per row had highly significant positive correlation with grain yield. However, the deviations between genotypic and phenotypic correlation and magnitude of environmental correlation suggested considerable influence of growing environment in expressing almost all the characters. Path coefficient analysis revealed that plant height (0.659), ear length (0.934) and kernel-rows per ear (0.715) had highly significant positive direct effect on grain yield suggesting their importance during selection. Simultaneous restricted selection should be done for number of kernel rows per ear.Bangladesh J. Agril. Res. 41(1): 173-182, March 2016