ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Electronic Resource

Molecular mapping of QTL for southwestern corn borer resistance, plant height and flowering in tropical maize (1998)

Khairallah, M. M. ; Bohn, M. ; Jiang, C. ; [et al.]

Oxford, UK : Blackwell Publishing Ltd

Plant breeding 117 (1998), S. 0

add to mindlist on the mindlist

Details

ISSN: 1439-0523

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Development of multiple insect resistance in tropical maize represents a major effort of the maize breeding programme at CIMMYT. Resistance to the southwestern corn borer (SWCB) is polygenically controlled with primarily additive gene action. Our main objective was to identify quantitative trait loci (QTL) involved in resistance to SWCB. Other objectives were to detect QTL in the same population for plant height, female flowering, and the anthesis-silking interval (ASI). A population of 472 F2 individuals derived from a cross between the susceptible line Ki3 and the resistant inbred CML139, was restriction fragment length polymorphism (RFLP) genotyped using 110 maize probes. F3 families were rated for leaf-feeding damage after artificial infestation at one location in three consecutive years. Height and flowering were measured in protected trials in two locations. QTL analyses were conducted using joint composite interval mapping. Seven QTL on chromosomes 3, 5, 6, 8, and 9 explained 30% of the phenotypic variance (σ2p) for SWCB damage. Most QTL alleles conferring resistance were contributed from CML139. QTL showed dominance, partial dominance and additive gene action. Eleven QTL dispersed across the genome were determined to affect plant height and explained 43% of σ2p. Four of these were in close proximity to loci with qualitative effects on plant height. Thirteen QTL (50% of sigma;2p) were identified for days to female flowering and nine (30% of σ2p) for ASI. Our results, along with those from other mapping studies at CIMMYT, are allowing us to formulate marker-assisted selection schemes to complement the breeding efforts for such complex traits as borer resistance.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1111/j.1439-0523.1998.tb01947.x

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

2

Electronic Resource

Comparison of QTLs mapped in RILs and their test-cross progenies of tropical maize for insect resistance and agronomic traits (1998)

Groh, S. ; Khairallah, M. M. ; González-de-León, D. ; [et al.]

Oxford, UK : Blackwell Publishing Ltd

Plant breeding 117 (1998), S. 0

add to mindlist on the mindlist

Details

ISSN: 1439-0523

Source: Blackwell Publishing Journal Backfiles 1879-2005

Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Notes: Quantitative trait loci (QTL) affecting resistance to south-western corn borer Diatraea grandiosella (SWCB) and sugarcane borer Diatraea saccharalis (SCB) have been identified previously in F2:3 lines and recombinant inbred lines (RILs) of tropical maize using restriction fragment length polymorphism (RFLP) analyses. Our objective was to determine whether QTLs identified in these generations are also expressed in test crosses (TC) of RILs. A population of 166 TC progenies was developed by crossing RILs from the cross CML131 (susceptible) × CML67 (resistant) with the unrelated, susceptible tester line CML216. Resistance to first-generation SWCB, measured as leaf-feeding damage (LFD) under artificial infestation, and other agronomic traits were evaluated in two environments for the TC progenies and three environments for 183 RILs. The correlation between line per se and TC performance was low for LFD and intermediate for most agronomic traits. Estimates of the genotypic variance and heritabilities were smaller in the TC progenies than in the RILs for all traits. Quantitative trait loci were identified using an RFLP linkage map with 136 loci. For LFD, four QTLs were detected in the TC progenies, of which two were in common with nine QTLs previously mapped in the RILs. Few QTLs for agronomic traits were common to the two types of progeny, because of the low consistency of QTL positions for all traits in RIL and TC progenies, the use of TC progenies should be considered in QTL mapping studies as the first step for marker-assisted selection in hybrid breeding.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1111/j.1439-0523.1998.tb01926.x

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

3

Electronic Resource

Genetic mapping of maize streak virus resistance from the Mascarene source. II. Resistance in line CIRAD390 and stability across germplasm (1999)

Pernet, A. ; Hoisington, D. ; Dintinger, J. ; [et al.]

Springer

Theoretical and applied genetics 99 (1999), S. 540-553

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Key words Quantitative trait loci ; Resistance mechanism ; MSV ; Composite interval mapping ; Tropical maize

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract The streak disease has a major effect on maize in sub-Saharan Africa. Various genetic factors for resistance to the virus have been identified and mapped in several populations; these factors derive from different sources of resistance. We have focused on the Réunion island source and have recently identified several factors in the D211 line. A second very resistant line, CIRAD390, was crossed to the same susceptible parent, B73. The linkage map comprised 124 RFLP markers, of which 79 were common with the D211×B73 map. A row-column design was used to evaluate the resistance to maize streak virus (MSV) of 191 F2:3 families under artificial infestation at two locations: Harare (Zimbabwe) and in Réunion island. Weekly ratings of resistance were taken and disease incidence and severity calculated. QTL analyses were conducted for each scoring date and for the integration over time of the disease scores, of incidence, and of severity. Heritability estimates (71–98%) were as high as for the D211×B73 population. Eight QTLs were detected on chromosomes 1, 2, 3, 5 (two QTLs), 6, 8, and 10. The chr1-QTL explained the highest proportion of phenotypic variation, about 45%. The QTLs on chromosomes 1, 2, and 10 were located in the same chromosomal bin as QTLs for MSV resistance in the D211×B73 population. In a simultaneous fit, QTLs explained together 43–67% of the phenotypic variation. The QTLs on chromosomes 3, 5, and 6 appeared to be specific for one or the other component of the resistance. For the chr3-QTL, resistance was contributed by the susceptible parent. There were significant QTL × environment interactions for some of the variables studied, but QTLs were stable in the two environments. They also appeared to be stable over time. Global gene action ranged from partial dominance to overdominance, except for disease severity. Some additional putative QTLs were also detected. The major QTL on chromosome 1 seemed to be common to the other sources of resistance, namely Tzi4, a tolerant line from IITA, and CML202 from CIMMYT. However, the distribution of the other QTLs within the genome revealed differences in Réunion germplasm and across these other resistance sources. This diversity is of great importance when considering the durability of the resistance.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001220051267

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

4

Electronic Resource

Several QTLs involved in osmotic-adjustment trait variation in barley (Hordeum vulgare L.) (1998)

Teulat, B. ; This, D. ; Khairallah, M. ; [et al.]

Springer

Theoretical and applied genetics 96 (1998), S. 688-698

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Key words Water stress ; Barley ; Osmotic adjustment ; Adaptation ; QTL ; Synteny

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Osmotic adjustment (OA) was previously demonstrated to be an important adaptive mechanism of drought tolerance in cereals. In order to determine which genomic regions are involved in OA variation, 187 barley (Hordeum vulgare L.) recombinant inbred lines (RILs) derived from a cross between Tadmor (drought tolerant) and Er/Apm (susceptible) were studied in a growth chamber for their OA capacity (through correlated traits and by calculation), at an early growth stage and under two water treatments (soil moisture of 14% and 100% of field capacity). The continuous distribution of the traits and their broad-sense line heritabilities, ranging from 0.04 to 0.44, indicated that OA and related traits should have a polygenic nature. A subset of 167 RILs were also genotyped using 78 RFLP, 32 RAPD and three morphological markers and a linkage map was constructed. Despite strong environmental effects acting on the traits, interval mapping and single-marker ANOVA allowed the detection of three QTLs for relative water content (RWC), four QTLs for osmotic potential (ψπ), two QTLs of osmotic potential at full turgor (ψπ100) and one QTL for osmotic adjustment at a soil moisture of 14% field capacity. For the irrigated treatment, only two QTLs were detected: one for RWC and one for ψπ100. Two chromosomal regions were involved in several OA-related trait variations and could be considered as regions controlling OA; these were present on chromosome 1 (7H) and chromosome 6 (6H), whereas other regions were specific for one trait. No major QTL was found. However, the genomic region involved in OA-related traits on chromosome 1 (7H) in barley seemed to be conserved for OA variation among cereals. Epistatic effects, with or without additive effects, acted on the traits.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/s001220050790

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

5

Electronic Resource

Mitochondrial DNA polymorphisms of Malawian bean lines: further evidence for two major gene pools (1990)

Khairallah, M. M. ; Adams, M. W. ; Sears, B. B.

Springer

Theoretical and applied genetics 80 (1990), S. 753-761

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Phaseolus vulgaris ; Mitochondrial RFLPs ; Gene pools ; Genetic diversity ; Malawi

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Summary Intraspecific mitochondrial DNA (mtDNA) diversity was determined in 23 Phaseolus vulgaris genotypes, and compared to previously observed variability of morphoagronomic characters and isozyme loci. Twenty of the lines were collected from Malawian landraces; the other three were pure-bred cultivars. The mtDNAs were digested with eight restriction endonucleases, revealing complex banding patterns. Southern hybridization using cosmid clones covering about 200-kb of the genome showed a considerable amount of uniformity of the mtDNA banding patterns. However, five restriction fragment length polymorphisms (RFLPs) were detected, dividing the bean lines into two groups corresponding to the previously known Mesoamerican and Andean gene pools of P. vulgaris. The cultivar “Mecosta” was separated from the rest of the lines by an additional RFLP. At least two out of the six RFLPs are believed to be due to base-pair mutation events. Our results provide the first evidence that the cytoplasms of the two major germ plasm pools of beans are distinct.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00224188

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

6

Electronic Resource

Mitochondrial restriction fragment length polymorphisms in wild Phaseolus vulgaris L.: insights on the domestication of the common bean (1992)

Khairallah, M. M. ; Sears, B. B. ; Adams, M. W.

Springer

Theoretical and applied genetics 84 (1992), S. 915-922

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Mitochondrial RFLPs ; Common bean ; Crop domestication ; Founder effect ; Gene pools

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Summary Previous examination of intraspecific mitochondrial DNA (mtDNA) diversity in common bean, Phaseolus vulgaris, showed that five restriction fragment length polymorphisms (RFLPs) distinguish the mitochondrial genomes of the two major gene pools of cultivated beans, the Mesoamerican and the Andean. In the study presented here, mtDNA was used to compare the amount of diversity in cultivated beans to that in collections of wild beans to gain an understanding of how and when the mitochondrial genomes of the gene pools became distinct. The mtDNA of six wild bean accessions from Central and South America were digested with nine restriction endonucleases and analyzed by Southern hybridization. A total of twenty RFLPs were detected demonstrating a significantly higher amount of mtDNA variability in wild beans than in cultivated ones. All of the wild beans had the same mtDNA pattern for four out of the five inter-gene pool RFLPs, indicating that the polymorphism arose soon after domestication: two in the gene pool of the cultivated Mesoamerican beans and two in the gene pool of the cultivated Andean beans. The fifth RFLP must have occurred before domestication since the locus was also polymorphic in the wild beans. Wild beans from the south Andes were distinct and less variable than wild accessions of the north Andes and Mesoamerica. The distribution of mtDNA RFLPs among the wild beans supports the concept of two distinct domestication events for P. vulgaris.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00227404

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

7

Electronic Resource

Mitochondrial genome size variation and restriction fragment length polymorphisms in threePhaseolus species (1991)

Khairallah, M. M. ; Adams, M. W. ; Sears, B. B.

Springer

Theoretical and applied genetics 82 (1991), S. 321-328

add to mindlist on the mindlist

Details

ISSN: 1432-2242

Keywords: Mitochondrial RFLPs ; Phaseolus ; Species relationships ; Genome size

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Summary Restriction patterns of mitochondrial DNA (mtDNA) from threePhaseolus species were examined to estimate their relative genome sizes and to determine the level of interspecific variability and relatedness. Three restriction endonucleases that produced relatively simple profiles were identified and used to determine the genome size of the three species. Taking into account fragment stoichiometries, the average estimates across enzymes were 456, 324, and 400 kb, respectively, forP. vulgaris, P. coccineus, andP. acutifolius. Restriction fragment length polymorphisms (RFLPs) differentiated the species when the mtDNAs were digested with seven endonucleases and hybridized with five cosmid clones covering ca. 200 kb of mtDNA sequences. Proportions of shared restriction fragments between every two species were computed as F-values and demonstrated thatP. vulgaris andP. coccineus are more related to each other than either is toP. acutifolius, and that the latter has a similar degree of relationship to the other two species.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF02190618

Permalink