Morphological Traits In Maize Research Articles

Prospecting quantitative trait loci for maydis leaf blight (MLB) resistance using a population of teosinte‐introgressed maize (Zea mays ssp. mays) and in silico identification of candidate MLB resistance genes

AbstractMaydis leaf blight (MLB) is an important fungal disease of maize causing yield losses of the magnitude of 38 to 46% worldwide. Present investigation aimed to identify stable and reliable MLB‐resistant QTLs and introgression maize lines to facilitate their utilization in future MLB resistance breeding programmes. For this purpose, 169 backcross inbred lines (BILs), derived using teosinte (Zea mays ssp. parviglumis) as one parent, were grown in randomized block design with two replications in two environments. The lines were phenotyped and genotyped to identify the resistant QTLs by single marker analysis (SMA) method. Also, twenty‐five most resistant and twenty‐five most susceptible lines were selected in order to mimic bidirectional selective genotyping to identify MLB‐resistant QTLs by trait‐based (SGTB) and marker‐based (SGMB) approach. Six and five MLB resistance QTLs were identified in S1 and S2, respectively, by SMA method, while twelve and eight MLB‐resistant QTLs were detected by SGTB and SGMB approach, respectively. A total of fifteen MLB resistance QTLs identified by either SMA, SGTB or SGMB co‐localized with forty‐two QTLs affecting eleven morphological traits in maize. Out of the MLB resistance QTLs detected in both S1 and S2 by SMA, two QTLs linked to marker umc2392 and umc1393 were stable. Four QTLs linked to marker umc1869, umc1720, umc1428 and umc1393 were detected by all three methods and were reliable. A total of 23 genes exhibiting response to fungal pathogens were identified by means of in silico analysis, and these may be validated further so as to be used in future maize improvement programmes.

Genetic Analysis and Heterosis Studies in 5×5 Diallel Crosses of Maize under the Meteorological Conditions of Rawalakot

This experiment was performed to evaluate heterosis and combining ability of morphological traits in maize (Zea mays L.). The experiment was arranged in randomized complete block design (RCBD) with three replicates. Twenty maize hybrids were obtained by 5×5 complete diallel crosses in first year and were evaluated for plant attributes like plant height, ear height, ear leaf area, flag leaf area, days to 50% silking, days to 50% pollen shed, anthesis-silking interval (ASI), no. of leaves per plant, no. of branches per tassel, no. of kernel rows per ear and kernels per row, 1000-kernel weight, shelling percentage, grain plus biological yield per plant and harvest index in second year. Among the crosses NCEV-4 × NCEV-3 (462.70g) showed maximum 1000-kernel weight, followed by NCEV-3 × EV-70040 (451.33g), while highest grain yield per plant was recorded for NCEV-4 × NCEV-3 (152.97g), followed by NCEV-3 × EV-70040 (145.10g). Maximum and highly significant heterosis and heterobeltiosis was found in cross NCEV-1530-11 × HNG (70.49 and 67.54), followed by HNG × EV-70040 (65.57 and 56.39) and HNG × NCEV-1530-11 (64.14 and 61.3), rest of the crosses also showed positive and highly significant heterosis and heterobeltiosis for grain yield per plant. Among the parents NCEV-3 has best GCA for grain yield (4.30) while cross NCEV-3 × NCEV-4 has best SCA for grain yield per plant (18.10) and could be used in hybridization for yield improvement.

Effect of reciprocal crosses on grain yield and other agronomic traits in maize

The goal of this experiment was to examine a possible influence of reciprocal crosses on grain yield and some morphological traits in maize. Field trials were set up on three locations (Zemun Polje, Pancevo, Becej) during 2015 and 2017. Five elite inbred lines were selected in order to produce hybrid combinations for the trial, two of them were of Lancaster origin and used as tester lines (ZPT1, ZPT2), while remaining three had a Non Lancaster origin (ZPL1, ZPL2 and ZPL3). By performing reciprocal crossings between Lancaster and non Lancaster inbred lines, twelve single cross hybrids were produced for the trial. Trials were set up on three locations during two years and grain yield, grain moisture, plant height, ear height and mass of 1000 kernels were analyzed. Location, year and reciprocal crosses were significant factors for all examined traits. Reciprocal crosses had statistical significance on two hybrid combinations in terms of grain yield and grain moisture. SNPs molecular markers were used to assess the genetic diversity of the inbred lines involved in this experiment. When it comes to plant height and mass of thousand kernels, a statistically significant difference was observed in one hybrid combination. The largest reciprocal differences between original and reciprocal hybrids were recorded in grain yield, which were statistically significant for the crosses ZPH4/ZPH4R and ZPH2/ZPH2R (20.03% and 19.49% respectively). The ZPH2/ZPH2R hybrid combination is the combination with the statistically significant differences between the original and reciprocal hybrid, for all evaluated traits except for grain moisture. Reciprocal hybrids ZPH5/ZPH5R and ZPH6/ZPH6R with ZPL3 as their maternal inbred line didn?t express a statistically significant differences between both variants, e.g. their reciprocal effect was low.

The impact of agroecological factors on morphological traits of maize

Climate changes are one of the crucial issues of modern agriculture. These changes imply the increase in average temperatures and the frequent occurrence of temperature extremes. Such conditions are stressful to maize concerning the expression of its traits. This paper presents the analysis of the maize yield concerning the yield components, morphological and chemical traits under various agroecological conditions. The objective of the study was to evaluate variability of grain yield (GY) and yield components (ear length, EL and number of kernel rows, NKR), morphological traits (plant height, PH and ear height, EH), as well as chemical traits (the whole plant dry matter, PDM and the ear dry matter, EDM), and the effect of the environment on the intensity of expression of these traits. Fifteen genotypes developed by crossing of six inbred lines were used as a material in the study carried out during the two-year period in one location. Obtained results indicate that traits were more pronounced in maize hybrids than in the parental components including the lower variability of the traits expression. NKR did not affect the yield unlike the EL, whose coefficient of determination was R2 = 0.600 in both production years. The environmental effect was high for all traits except NKR. PDM and EDM were closely related to PH and EH, but they also depended on the EL and the NKR. Variations in meteorological conditions have a significant impact on the final goal of the production, the yield. Prevailing agro-ecological conditions should be a major guideline in planning the crop production and selecting the genetic material.

Effect of Nanofertilizers and Biofertilizers on Yield of Maize: Biplot Analysis

AbstractOne of the newest and most interesting fields of science is nanotechnology, which is exploiting many areas such as life sciences; however, its application in agriculture is rarely studied. In order to examine the environmentfriendly fertilizers (nano-sized and biological fertilizers), and control the agricultural nonpoint source pollution from the source, a field experiment was arranged to study the effects of bulk fertilizers (NPK, nitrogen biofertilizer, and phosphorus biofertilizer), nanofertilizers (nanoboron, nanozinc and nanocomplete) and no fertilizer treatment (control) on morphological traits of maize. The first two Principal Components (PCs) were used to create a biplot, which accounted for 72% of the variance of the treatment × trait interaction. The nanozinc fertilizers following nanoboron fertilizer were the best in most of the biological yield, seed yield, harvest index, and 100-grain weight. The vector-view biplot revealed a strong positive association between chlorophyll and protein content, seed yield with the number of kernels per ears and the number of rows per kernel. Nanocomplete fertilizer was the best treatment for chlorophyll content, protein percent and straw yield, while NPK did not high increase in the most traits of maize. This investigation indicated that treatment × trait biplot can graphically show the interrelationships among traits and facilitate visual comparison of fertilizers. In conclusion, it was found that zinc and boron nanofertilizers increased the production of most of the traits in maize. This study indicated that nano types of fertilizers could promote the studied traits in maize plant.

Comparative QTL analysis for yield components and morphological traits in maize (Zea mays L.) under water-stressed and well-watered conditions.

Drought significantly influences maize morphology and yield potential. The elucidation of the genetic mechanisms of yield components and morphological traits, and tightly linked molecular markers under drought stress are thus of great importance in marker assisted selection (MAS) breeding. Here, we identified 32 QTLs for grain weight per ear, kernel ratio, and ear height-to-plant height ratio across two F2:3 populations under both drought and non-drought conditions by single-environment mapping with composite interval mapping (CIM), of which 21 QTLs were mapped under water-stressed conditions. We identified 29 QTLs by joint analysis of all environments with mixed-linear-model-based composite interval mapping (MCIM), 14 QTLs involved in QTL-by-environment interactions, and 11 epistatic interactions. Further analysis simultaneously identified 20 stable QTLs (sQTLs) by CIM and MCIM could be useful for genetic improvement of these traits via QTL pyramiding. Remarkably, bin 1.07-1.10/6.05/8.03/8.06 exhibited four pleiotropic sQTLs that were consistent with phenotypic correlations among traits, supporting the pleiotropy of QTLs and playing important roles in conferring growth and yield advantages under contrasting watering conditions. These findings provide information on the genetic mechanisms responsible for yield components and morphological traits that are affected by different watering conditions. Furthermore, these alleles provide useful targets for MAS.

Genetic control observation for yield and morphological traits in maize (Zea mays L.) inbred lines

Genetic control observation for yield and morphological traits in maize (Zea mays L.) inbred lines

Analysis of the genetic architecture of maize ear and grain morphological traits by combined linkage and association mapping.

Using combined linkage and association mapping, 26 stable QTL and six stable SNPs were detected across multiple environments for eight ear and grain morphological traits in maize. One QTL, PKS2, might play an important role in maize yield improvement. In the present study, one bi-parental population and an association panel were used to identify quantitative trait loci (QTL) for eight ear and grain morphological traits. A total of 108 QTL related to these traits were detected across four environments using an ultra-high density bin map constructed using recombinant inbred lines (RILs) derived from a cross between Ye478 and Qi319, and 26 QTL were identified in more than two environments. Furthermore, 64 single nucleotide polymorphisms (SNPs) were found to be significantly associated with the eight ear and grain morphological traits (-log10(P) > 4) in an association panel of 240 maize inbred lines. Combining the two mapping populations, a total of 17 pleiotropic QTL/SNPs (pQTL/SNPs) were associated with various traits across multiple environments. PKS2, a stable locus influencing kernel shape identified on chromosome 2 in a genome-wide association study (GWAS), was within the QTL confidence interval defined by the RILs. The candidate region harbored a short 13-Kb LD block encompassing four SNPs (SYN11386, PHM14783.16, SYN11392, and SYN11378). In the association panel, 13 lines derived from the hybrid PI78599 possessed the same allele as Qi319 at the PHM14783.16 (GG) locus, with an average value of 0.21 for KS, significantly lower than that of the 34 lines derived from Ye478 that carried a different allele (0.25, P < 0.05). Therefore, further fine mapping of PKS2 will provide valuable information for understanding the genetic components of grain yield and improving molecular marker-assisted selection (MAS) in maize.

Chemical constituents of Cinnamomum septentrionale leaf litter and its allelopathic activity on the growth of maize (Zea mays)

A pot experiment was conducted to study the effect of decomposing Cinnamomum septentrionale leaf litter on the growth of maize. In this study, the morphological traits of maize were significantly inhibited when the leaf litter amount reached or exceeded 40 g per pot; Furthermore, during the early growth stage or with a large amount of litter addition, the pigment contents were inhibited by C. septentrionale leaf litter. Gas chromatography–mass spectrometry was used to determine the volatile substances of leaf litter and 34 compounds were identified, several of which were reported to be phytotoxic. In conclusion, the leaf litter of C. septentrionale showed a strong allelopathic effect on the growth of maize. Thus, it is better to avoid the growing of maize under or near the C. septentrionale plantation unless the leaf litter could be eliminated in time or other effective leaf litter processing methods could be implemented.

Correlation and path analysis of agronomic and morphological traits in maize

The efficiency of selection can be broadened for certain traits using estimative of genetic parameters, which are fundamental for plant breeding. The estimative of genetic parameters allows identifying the nature of the action of genes involved in the control of quantitative traits and evaluates the efficiency of different breeding strategies to obtain genetic gains. Therefore, this study aimed to verify the variability and correlation between morphological and agronomic traits in synthetic maize populations, in order to practice indirect selection. Thirteen populations were evaluated in field experiments at Jaboticabal- SP and Campo Alegre de Goias-GO, using randomized block design, for lodging (LOD), culm breakage (CB), plant height (PH), ear height (EH) and grain yield (GY). The 13 populations were also sown in 1 kg-plastic bags under black shade cloth, using a randomized complete block design with nine replications, for evaluation of the morphological traits: main root length (MRL), root fresh matter (RFM), root dry matter (RDM), average root diameter (ARD), root surface area (RSA), root tissue density (RTD) and shoots dry matter (SDM). The trait GY exhibited genetic variability enough to be effective if used for selection. The selection on the morphological traits is indicated on RDM, due to the ease in obtaining data and its accuracy, high correlation with all morphological traits and association with GY. The simultaneous selection based on RFM and RDM, for gains in GY, can be performed. The highest direct effect on GY was identified in LOD and CB, being indicated for indirect selection.

Variance components and association between corn hybrids morpho-agronomic characters

The present work aimed at evaluating the canonical correlations between traits of grain yield and morphological traits in maize, in order to verify the associations and interdependence among groups. The experiment was conducted in the agricultural year 2010/2011; consisted of 25 corn hybrids, allocated in five locations of the states of Parana, Santa Catarina e Rio Grande do Sul. Settled two groups of traits, with Group I comprised agronomic characters of grain yield: grain yield plot, the total weight of grains and weight of hundred grains and the group II formed by morphology: stem diameter , leaf angle , tassel length , number of tassel branches , total leaf area , insertion of the ear , plant height in maize. The first, second and third canonical pair proved signifi­cant at the 1% level of probability, using the chi-square test, indicating that the groups are not independent. Hybrids with higher plant height, insertion of ear and leaf angle and fewer branches and tassel length are asso­ciated with the increase in weight of hundred grains in maize. To increase the grain weight, should be consid­ered hybrids with greater insertion of the ear, leaf area and shorter length of the tassel. The increase in leaf area, as well as smaller tassel length is related positively to increase grain yield in maize.

Heterotic loci for various morphological traits of maize detected using a single segment substitution lines test-cross population

Heterosis has been exploited to increase grain yield, quality, and resistance in many crops, and it plays an important role in plant breeding. However, the genetic mechanism of heterosis remains unclear. To dissect the genetic basis of heterosis, a set of 203 single segment substitution lines (SSSLs) was developed, and its test-cross population was used to identify heterotic loci (HL) for plant morphological traits in maize, including plant height (PH), ear height (EH), leaf number (LN), tassel main axis length (TMAL), and tassel branch number (TBN). A total of 41 QTLs and 37 HL were identified for five morphological traits in the test-cross population derived from the 203 SSSLs and the parent, Xu178. Nine HL for PH, nine HL for EH, seven HL for LN, seven HL for TMAL, and five HL for TBN were detected in three different environments, respectively. Eight HL, ph1a, ph1b, ph2, ph5, eh3a, eh3b, eh10, and tmal1b, were simultaneously detected in the three environments. Among the 37 HL, only 10 (27.03 %; for PH, EH, LN, and TBN) had a corresponding QTL (24.39 %) sharing the same chromosomal region. Of all the HL, 21.4 % showed dominance effects, 76.8 % showed over-dominance effects, and only one (1.8 %) showed a partial-dominance effect. This result illustrated that heterosis and performance was controlled by different genetic mechanisms, and over-dominance effects were the main contributors to heterosis for plant-related traits at the single-locus level in maize.

Effects of biochar application on morphological traits in maize and soybean

This paper analyses the effects of the biochar application morphologi?cal traits in maize and soybean under semi-controlled conditions. During the study, the in?creasing doses of biochar (0%, 0.5%, 1, 3, and 5%) were incorporated in three soil types: Alluvium, Humogley and Chernozem to determine plant height and shoot weight. The ex?periment was set up as fully randomized design with three repetitions. The plants were grown in pots of 5 l with controlled watering and N fertilization. The research results have shown that there are differences in terms of biochar effects on soils. The greatest effect on plant height and shoot weight was obtained when the biochar was applied to Humogley soil and lower effects were found on the Alluvium soil. The increase in aboveground mass of maize and soybeans was significantly conditioned by adding different doses of biochar. Based on these results, it can be concluded that adding biochar can significantly affect the growth of plants. This is a consequence of the changes it causes in soil, which requires further tests to complement the current findings.

Quantitative trait loci for yield and morphological traits in maize under drought stress

Drought is one of the most important factors contributing to crop yield loss. In order to develop maize varieties with drought tolerance, it is necessary to explore the genetic basis. Mapping quantitative trait loci (QTL) that control the yield and associate agronomic traits is one way of understanding drought genetics. QTLs associated with grain yield (GY), leaf width (LW3, LW4) plant height (PH), ear height (EH), leaf number (NL), tassel branch number (TBN) and tassel length (TL) were studied with composite interval mapping. A total of 43 QTLs were detected, distributed on all chromosomes, except chromosome 9. Phenotypic variability determined for the identified QTLs for all the traits was in the range from 20.99 to 87.24%. Mapping analysis identified genomic regions associated with two traits in a manner that was consistent with phenotypic correlation among traits, supporting either pleiotropy or tight linkage among QTLs.

Molecular-marker-facilitated studies of morphological traits in maize. II: Determination of QTLs for grain yield and yield components

Genetic factors controlling quantitative inheritance of grain yield and its components have not previously been investigated by using replicated lines of an elite maize (Zea mays L.) population. The present study was conducted to identify quantitative trait loci (QTLs) associated with grain yield and grain-yield components by using restriction fragment length polymorphism (RFLP) markers. A population of 150 random F2∶3 lines was derived from the single cross of inbreds Mo17 and H99, which are considered to belong to the Lancaster heterotic group. Trait values were measured in a replicated trial near Ames, Iowa, in 1989. QTLs were located on a linkage map constructed with one morphological and 103 RFLP loci. QTLs were found for grain yield and all yield components. Partial dominance to overdominance was the primary mode of gene action. Only one QTL, accounting for 35% of the phenotypic variation, was identified for grain yield. Two to six QTLs were identified for the other traits. Several regions with pleiotropic or linked effects on several of the yield components were detected.

Is the polymorphism of protein amounts related to phenotypic variability? A comparison of two-dimensional electrophoresis data with morphological traits in maize

The hypothesis that the quantitative variations in gene product levels could be a more important basis for morphological and adaptative change than the classical qualitative variability revealed by electrophoretic techniques was studied by comparing five maize lines from three sets of variables: (i) qualitative variations of proteins (presence/absence) revealed by two-dimensional polyacrylamide gel electrophoresis (2D PAGE), at a physiological seedling stage; (ii) quantitative variations in proteins (spots more or less intense) revealed by 2D PAGE, at the same physiological stage; (iii) general combining abilities of fourteen heritable, morphological or agronomical characters measured at various juvenile and adult stages. Distances between lines were defined, based on qualitative and quantitative variations of proteins. These distances do not appear to be correlated and do not give the same patterns of divergence between lines, as shown by principal coordinate analyses. Mahalanobis distances computed from the general combining abilities of the morphological characters are significantly correlated (r=0.75) to quantitative but not to qualitative distances. The comparison of the first planes of the principal coordinate analyses performed on the three kinds of distances clearly confirms this finding. Our results are discussed in connection with the possible genetic meaning of the two molecular distances and with the hypothesis that regulatory processes are primarily implicated in morphological variation.