Genetic analysis of tolerance to maize streak virus in maize

Genome ◽  
1999 ◽  
Vol 42 (1) ◽  
pp. 20-26 ◽  
Author(s):  
D T Kyetere ◽  
R Ming ◽  
M D McMullen ◽  
R C Pratt ◽  
J Brewbaker ◽  
...  
Keyword(s):  
Zea Mays ◽  
Field Experiments ◽  
Zea Mays L ◽  
Recombinant Inbred Lines ◽  
Interval Mapping ◽  
Chromosome 1 ◽  
Rflp Markers ◽  
Streak Virus ◽  
Phenotypic Variance ◽  
Progress Curve

Maize streak, incited by maize streak geminivirus (MSV), is a major disease limiting maize (Zea mays L.) production over widespread areas of Africa. To understand the genetic basis of tolerance to MSV, recombinant inbred lines (RILs) derived from the cross of the MSV tolerant inbred Tzi4 with the MSV susceptible inbred Hi34, were evaluated for MSV tolerance. Experiments were conducted using controlled leafhopper (Cicadulina spp.) infestation in one glasshouse experiment at Namulonge, Uganda, and two field experiments at Centro Internacional de Mejoramiento de Maiz y Trigo, Harare, Zimbabwe. Eighty-seven RILs were genotyped at 82 loci by restriction fragment length polymorphism (RFLP) analysis. The association between genotype at RFLP marker loci and MSV tolerance was determined using single-factor analysis of variance (SFAOV), multiple regression, and interval mapping procedures. There was a significant association of MSV tolerance with RFLP markers on the short arm of chromosome 1. By SFAOV, the portion of the phenotypic variance explained by genotype class (R2) for the association between npi262 and the area under disease progress curve (AUDPC) measure of MSV tolerance was as high as 76% in field experiments. Interval mapping analyses (Knapp and Bridges 1990; Nelson 1997) identified the chromosome region bracketed by bnl12.06a and npi262 as explaining the largest proportion of the variation in MSV tolerance. After classification of symptom responses from the final field ratings into resistant and susceptible classes, qualitative analysis of data fit a chi-square test to a 1:1 Mendelian ratio, further indicating presence of a single major gene. Multipoint linkage analysis placed this gene, designated msv1, at a genetic distance of 3 cM distal to npi262. Identification of the tightly linked molecular marker locus npi262 should greatly aid ongoing conversion of susceptible African varieties to maize streak resistance.Key words: Zea mays L., Cicadulina spp., host resistance, gene mapping, molecular markers.

scholarly journals Identification of quantitative trait loci for leaf traits in rice

Genetika ◽  
2016 ◽  
Vol 48 (2) ◽  
pp. 643-652 ◽  
Author(s):  
Baoyan Jia ◽  
Xinhua Zhao ◽  
Yang Qin ◽  
Muhammad Irfan ◽  
Tae-Heon Kim ◽  
...  
Keyword(s):  
Recombinant Inbred Lines ◽  
Leaf Traits ◽  
Rice Cultivar ◽  
Interval Mapping ◽  
Mapping Method ◽  
Japonica Rice ◽  
Phenotypic Variance ◽  
Simple Sequence ◽  
Variance Explained ◽  
Map Distance

A recombinant inbred lines (RILs) population of 90 lines were developed from a subspecies cross between an indica type cultivar, ?Cheongcheong?, and a japonica rice cultivar, ?Nagdong? was evaluated for leaf traits in 2009. A genetic linkage map consisting of 154 simple sequence repeat (SSR) markers was constructed, covering 1973.6 cM of 12 chromosomes with an average map distance of 13.9 cM between markers. By composite interval mapping method a total of 19 QTLs were identified for the leaf traits on 5 chromosomes (Chr.1, Chr.3, Chr.6, Chr.8 and Chr.11). The percentage of phenotypic variance explained by each QTL varied from 8.1% to 29.4%. Five pleiotropic effects loci were identified on chromosomes 1,6.

Microsatellite markers linked to QTL for resistance to Mal de Río Cuarto disease in Zea mays L.

2004 ◽  
Vol 142 (3) ◽  
pp. 289-295 ◽  
Author(s):  
M. A. DI RENZO ◽  
N. C. BONAMICO ◽  
D. G. DÍAZ ◽  
M. A. IBAÑEZ ◽  
M. E. FARICELLI ◽  
...  
Keyword(s):  
Zea Mays ◽  
Inbred Line ◽  
Quantitative Trait ◽  
Dominant Gene ◽  
Phenotypic Selection ◽  
Severity Index ◽  
Viral Disease ◽  
Interval Mapping ◽  
Phenotypic Variance ◽  
Ssr Loci

‘Mal de Río Cuarto’ (MRC) disease, caused by a member of the family Reoviridae belonging to the genus Fijivirus, is considered to be the most damaging viral disease of maize (Zea mays L.) in Argentina. Resistance to MRC disease is a quantitative trait with moderate heritability ranging from 0·44 to 0·56. The objective of this study was to identify simple sequence repeats (SSR) loci linked to quantitative trait loci (QTL) contributing to MRC disease resistance. Two hundred and twenty-seven F3 derived-lines from a cross between a susceptible inbred line, Mo17, and a partially resistant inbred line, BLS14, were evaluated across four Río Cuarto environments. A disease severity index (DSI) based on disease grades was calculated and used to rate F3 derived-lines for their resistance to MRC disease. A subset of parental F2 plants belonging to susceptible and resistant F3 derived-lines from field assessments was assayed for 180 SSR primer pairs to map resistance genes. Fifty-six maize SSR were employed for the testing of linkage among DNA markers and the mapping of QTL through composite interval mapping. Resistance to MRC disease was affected by two QTL on chromosomes 1 and 8 which showed overdominance and dominant gene action, respectively. A simultaneous fit with these QTL in the joint analyses explained 36·2% of the phenotypic variance. In spite of the fact that relative efficiency of marker-assisted selection (MAS) in comparison to phenotypic selection was close to 1, the mapped QTL could improve the efficiency of efforts in breeding for resistance to MRC disease.

scholarly journals Effect of nitrogen fertilization on metabolisms of essential and non-essential amino acids in field-grown grain maize (Zea mays L.)

2010 ◽  
Vol 56 (No. 12) ◽  
pp. 574-579 ◽  
Author(s):  
T. Lošák ◽  
J. Hlušek ◽  
R. Filipčík ◽  
L. Pospíšilová ◽  
J. Maňásek ◽  
...  
Keyword(s):  
Amino Acids ◽  
Zea Mays ◽  
Field Experiments ◽  
Zea Mays L ◽  
Tricarboxylic Acid Cycle ◽  
Essential Amino Acids ◽  
Isoleucine Leucine ◽  
N Dose ◽  
Limiting Amino Acid ◽  
Nitrogen Rates

In two-year field experiments, nitrogen (N) in the form of urea (0, 120 and 240 kg N/ha) was applied to grain maize (Zea mays L.) hybrid KWS 2376. The two-year mean content of total grain N at harvest was 1.54%. The highest N dose reduced most of the 17 amino acids (AA) analysed in the grain compared with the other treatments. Possible reasons for this could be an adverse effect on the tricarboxylic acid cycle or deficiency of carbon skeletons for the assimilation of NH<sub>4</sub><sup>+</sup> into amides and amino acids. The content of the limiting amino acid lysine was not influenced by N fertilisation, with a mean two-year content of 2.02 mg/g DM. Taking into account the differences in fertilisation, the effect of the year was seen in the maximal accumulation of amino acids serine, proline, methionine, threonine, arginine and lysine. Increasing rates of nitrogen reduced the accumulation of asparagine and glycine, and, on the contrary, increased the accumulation of tyrosine. Nitrogen rates have a significant effect on the maximal accumulation of valine, isoleucine, leucine, phenylalanine, histidine, cysteine and alanine and appeared as early as after the first increased rate of nitrogen (120 kg N/ha).

scholarly journals Mapping QTL for Grain Yield under Moisture Stress Environments in Rice (Oryza sativa L.)

2011 ◽  
Vol 3 (4) ◽  
pp. 129-133
Author(s):  
Supriyo CHAKRABORTY ◽  
Sheng-Chu WANG ◽  
Zhao-Bang ZENG
Keyword(s):  
Grain Yield ◽  
Genetic Variance ◽  
Oryza Sativa L ◽  
Moisture Stress ◽  
Interval Mapping ◽  
Chromosome 1 ◽  
Phenotypic Variance ◽  
Common Qtl ◽  
Rice Chromosomes ◽  
Stress Environments

Polygenes (QTLs) for grain yield were mapped on rice chromosomes under two moisture stress environments by multiple interval mapping (MIM) method in a double haploid (DH) population derived from a cross between a deep-rooted japonica and a shallow-rooted indica genotype. In environment 1 (E1), the MIM detected a total of six QTLs for grain yield on chromosomes-two QTLs on chromosome 1 and four QTLs on chromosome 5 along with one additive x additive epistasis. But in environment 2 (E2), the MIM detected five QTLs for grain yield on two chromosomes-three QTLs on chromosome 1 and two QTLs on chromosome 7. One common QTL on chromosome 1 flanked by the markers RG109-ME1014 was detected in both the environments, although the other detected QTLs differed between environments. The magnitude of QTL effect, percent genetic variance and percent phenotypic variance explained by each QTL was also estimated in both environments. The common QTL explained about 26.05 and 13.93% of genetic variance in E1 and E2, respectively. Estimated broad sense heritability for grain yield was 48.01 in E1 and 25.27% in E2.

QTL mapping for seedling morphology under drought stress in wheat cross synthetic (W7984)/Opata

2018 ◽  
Vol 16 (4) ◽  
pp. 359-366
Author(s):  
Maria Khalid ◽  
Alvina Gul ◽  
Rabia Amir ◽  
Mohsin Ali ◽  
Fakiha Afzal ◽  
...  
Keyword(s):  
Drought Stress ◽  
Recombinant Inbred Lines ◽  
Genotyping By Sequencing ◽  
Interval Mapping ◽  
Wheat Breeding ◽  
Seedling Stage ◽  
Poor Correlation ◽  
Root Weight ◽  
Phenotypic Variance ◽  
Seedling Morphology

AbstractDrought stress ‘particularly at seedling stage’ causes morpho-physiological differences in wheat which are crucial for its survival and adaptability. In the present study, 209 recombinant inbred lines (RILs) from synthetic wheat (W7984)× ‘Opata’ (also known as SynOpRIL) population were investigated under well-watered and water-limited conditions to identify quantitative trait loci (QTL) for morphological traits at seedling stage. Analysis of variance revealed significant differences (P < 0.01) among RILs, and water treatments for all traits with moderate to high broad sense heritability. Pearson's coefficient of correlation revealed positive correlation among all traits except dry root weight that showed poor correlation with fresh shoot weight (FSW) under water-limited conditions. A high-density linkage map was constructed with 2639 genotyping-by-sequencing markers and covering 5047 cM with an average marker density of 2 markers/cM. Composite interval mapping identified 16 QTL distributed over nine chromosomes, of which six were identified under well-watered and 10 in water-limited conditions. These QTL explained from 4 to 59% of the phenotypic variance. Six QTL were identified on chromosome 7B; three for shoot length under water-limited conditions (QSL.nust-7B) at 64, 104 and 221 cM, two for fresh root weight (QFRW.nust-7B) at 124 and 128 cM, and one for root length (QRL.nust-7B) at 122 cM positions. QFSW.nust-7B appeared to be the most significant QTL explaining 59% of the phenotypic variance and also associated with FSW at well-watered conditions. These QTL could serve as target regions for candidate gene discovery and marker-assisted selection in wheat breeding.

Comparison of RAPD and RFLP markers for mapping F2 generations in maize (Zea mays L.)

1996 ◽  
Vol 93 (4) ◽  
pp. 606-612 ◽  
Author(s):  
V. H. Beaumont ◽  
J. Mantet ◽  
T. R. Rocheford ◽  
J. M. Widholm
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Rflp Markers

Postemergence control of quackgrass [Elytrigia repens (L) Nevski] with DPX-79406 in corn (Zea mays L)

1994 ◽  
Vol 74 (2) ◽  
pp. 375-381 ◽  
Author(s):  
M. E. Reidy ◽  
C. J. Swanton
Keyword(s):  
Zea Mays ◽  
Key Words ◽  
Significant Interaction ◽  
Growth Stage ◽  
Field Experiments ◽  
Zea Mays L ◽  
Optimum Dose ◽  
Corn Yield ◽  
Leaf Stage ◽  
Elytrigia Repens

Laboratory and field experiments were established to determine the optimum dose and timing of postemergence applications of DPX-79406 for quackgrass control. Four node quackgrass rhizome fragments from each biotype were grown under controlled conditions. At the three-to-four-leaf stage, quackgrass plants were sprayed with DPX-79406 and evaluated for control. A significant response of quackgrass biotypes to DPX-79406 was evident only at lower doses. In the field, quackgrass was effectively controlled by all doses of DPX-79406. Significant growth-stage effects were observed for quackgrass shoot and rhizome dry weights in the year of application and in the year following application. There was a significant interaction between year and growth stage. In 1990, quackgrass biomass was greater when DPX-79406 was applied at the two-to-three-leaf stage of quackgrass than at the four-to-five-leaf stage. In 1991, however, the opposite occurred. Within a growth stage, the 6.25 g ha−1 dose was as effective for controlling quackgrass as 18.5 g ha−1, in both years of the study. In 1991, significant decreases in corn yield were observed for DPX-79406 doses of > 12.5 g ha−1 applied at the four-to-five-leaf stage of quackgrass. For all the variables studied, DPX-79406 doses of 6.25–12.5 g ha−1 resulted in consistent control of quackgrass. Key words: DPX-79406, nicosulfuron, rimsulfuron, quackgrass, Elytrigia repens, corn, Zea mays

Bromoxynil tolerance during the seedling phase is associated with genetic grain yield improvement in maize

1991 ◽  
Vol 71 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
M. Tollenaar ◽  
M. Mihajlovic
Keyword(s):  
Zea Mays ◽  
Chlorophyll Fluorescence ◽  
Grain Yield ◽  
Stress Tolerance ◽  
Field Experiments ◽  
Zea Mays L ◽  
Environmental Stresses ◽  
Yield Improvement ◽  
Maize Hybrids ◽  
Highly Correlated

Genetic grain yield improvement of maize (Zea mays L.) in Ontario during the past three decades can be attributed, in part, to increased tolerance to environmental stresses. We have observed a differential response of field-grown old and new hybrids after application of the photosystem II inhibiting herbicide bromoxynil (4-hydroxy-3,5-dibromobenzonitrile). Studies were conducted to test whether tolerance to bromoxynil is associated with stress tolerance and grain yield in maize hybrids representing three decades of yield improvement in Ontario. Experiments were carried out with seedlings of eight maize hybrids grown in pots in controlled-environment growth cabinets and, in one experiment, with seedlings grown in pots outside during the months of July and August at Guelph, Ontario. Bromoxynil was applied to the youngest fully-expanded leaf of plants at the 6- to 8-leaf stage and chlorophyll fluorescence of the treated leaves was measured in the 2- to 24-h period after bomoxynil application. Results showed that the chlorophyll fluorescence ratio Fv/Fm, an indicator of photosynthetic efficiency, declined after bromoxynil application until 4 h after application and, subsequently, recovered slightly during the next 20 h. Large differences in the Fv/Fm ratio were apparent among hybrids in the response to bromoxynil. The Fv/Fm ratio was significantly higher for hybrids released in the 1980s than for hybrids released in the 1970s, and the Fv/Fm ratio of the latter group was significantly higher than that of the four oldest hybrids. Chlorophyll fluorescence ratios Fv/Fm after bromoxynil application in the seedling phase were highly correlated with grain yield of the hybrids in field experiments conducted during 1987 and 1988 (r = 0.91). Results of this study support the contention that maize genotypes that are less sensitive to bromoxynil are less susceptible to environmental stresses. Key words: Zea mays L., stress tolerance, bromoxynil, chlorophyll fluorescence, Fv/Fm ratio, detoxifying agents

SLOW RELEASE N FERTILIZERS APPLIED IN FALL FOR CORN

1977 ◽  
Vol 57 (4) ◽  
pp. 487-496 ◽  
Author(s):  
E. G. BEAUCHAMP
Keyword(s):  
Zea Mays ◽  
Field Experiments ◽  
Zea Mays L ◽  
Slow Release ◽  
Soil Layers ◽  
N Fertilizers ◽  
Residual N ◽  
Coated Urea ◽  
Sampling Times ◽  
Fall Application

Slow release N fertilizers were considered as efficient sources of N for fall application to corn (Zea mays L.). Accordingly, sulfur-coated urea (SCU) and crotonylidene di-urea (CDU) were compared with urea in several field experiments. Neither SCU nor CDU were shown to be advantageous over urea in terms of grain yield. Similarly, the N content of the leaf opposite and below the ear did not show a greater availability of N from SCU and CDU than from urea applied in the fall. Response to residual N from previous applications of urea, SCU, and CDU was obtained for 2 yr after application. There was a tendency for a greater response to residual SCU. The concentration of NO−3 in the 0- to 18- and 18- to 36-cm soil layers was usually less with slow release N fertilizers than urea at early May sampling times. By mid-June, the NO−3 concentration had increased substantially with both urea and the slow release N fertilizers. In 2 yr when urea was also applied in the spring, the NO−3 concentration with spring-applied urea was higher than with fall-applied urea. This reflects the greater loss of N during the winter months with fall-applied urea. After growth terminated in the fall, NO−3 apparently continued to be released from urea and slow release N fertilizers at similar rates. Thus slow release N fertilizers also have potential to contribute significantly to the NO−3 concentration in drainage and groundwaters. In general, there was no noteworthy difference between SCU and CDU in this study. Also, slow release N fertilizers did not show any agronomic advantage over urea when applied in the fall.

Relationship between lodging, morphological characters and yield of varieties of maize (Zea mays L.)

1978 ◽  
Vol 91 (3) ◽  
pp. 633-638 ◽  
Author(s):  
S. U. Remison ◽  
Dele Akinleye
Keyword(s):  
Zea Mays ◽  
Field Experiments ◽  
Zea Mays L ◽  
Growing Season ◽  
Morphological Characters ◽  
Growing Seasons ◽  
Basal Internode ◽  
Ear Height ◽  
The Relationship ◽  
Rainforest Zone

SummaryField experiments were carried out in the early and late growing seasons in the rainforest zone of Nigeria to find out the relationship between lodging, morphological characters and yield of maize.Morphological characters associated with lodging were plant height, ear height and length of basal internode. There was a negative correlation between lodging and yield. Much of the lodging recorded, especially in the early growing season, was due to weak stems. Earliness, diameter of stem and leaf area had no relationship with lodging.

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