A STUDY ON THE STRUCTURE OF GENE Rp3 FOR RUST RESISTANCE IN ZEA MAYS

1974 ◽  
Vol 16 (4) ◽  
pp. 857-860 ◽  
Author(s):  
K. M. S. Saxena ◽  
A. L. Hooker
Keyword(s):  
Zea Mays ◽  
Rust Resistance ◽  
Zea Mays L ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Crossing Over ◽  
Puccinia Sorghi ◽  
Complex Locus

In maize (Zea mays L.) Rp3 expresses itself as a dominant gene for resistance to Puccinia sorghi Schw. culture 90laba and as a recessive gene for resistance to culture 933a. Suspecting that Rp3 is a complex locus consisting of two closely linked genes, efforts were made to separate the two putative genes by crossing over. Maize lines heterozygous for resistance and glossy leaf genes (Rp3 - Gl6/rp3 - gl6) were crossed with inbreds homozygous for susceptibility and glossy leaves (rp3 - gl6/rp3 - gl6). The testcross progeny, consisting of 4802 seedlings, was tested with culture 90laba. Fifty-seven recombinant seedlings, resistant to culture 90laba and glossy, were isolated and grown to maturity. These were selfed and their progeny tested to identify those that may have arisen from crossing over within region Rp3. No recombinants of this nature were found. If Rp3 is a complex locus, the two genes comprising it could not be more than 0.06 map units apart.

scholarly journals Genetic and Molecular Characterization of the Maizerp3Rust Resistance Locus

Genetics ◽  
2002 ◽  
Vol 162 (1) ◽  
pp. 381-394 ◽  
Author(s):  
Craig A Webb ◽  
Todd E Richter ◽  
Nicholas C Collins ◽  
Marie Nicolas ◽  
Harold N Trick ◽  
...  
Keyword(s):  
Family Members ◽  
Crossing Over ◽  
Resistance Locus ◽  
Leucine Rich Repeat ◽  
Bac Contig ◽  
Puccinia Sorghi ◽  
Coding Regions ◽  
Complex Locus ◽  
Sequence Identities

AbstractIn maize, the Rp3 gene confers resistance to common rust caused by Puccinia sorghi. Flanking marker analysis of rust-susceptible rp3 variants suggested that most of them arose via unequal crossing over, indicating that rp3 is a complex locus like rp1. The PIC13 probe identifies a nucleotide binding site-leucine-rich repeat (NBS-LRR) gene family that maps to the complex. Rp3 variants show losses of PIC13 family members relative to the resistant parents when probed with PIC13, indicating that the Rp3 gene is a member of this family. Gel blots and sequence analysis suggest that at least 9 family members are at the locus in most Rp3-carrying lines and that at least 5 of these are transcribed in the Rp3-A haplotype. The coding regions of 14 family members, isolated from three different Rp3-carrying haplotypes, had DNA sequence identities from 93 to 99%. Partial sequencing of clones of a BAC contig spanning the rp3 locus in the maize inbred line B73 identified five different PIC13 paralogues in a region of ∼140 kb.

Terminal ear mutant of maize (Zea mays L.)

1974 ◽  
Vol 82 (3) ◽  
pp. 433-435 ◽  
Author(s):  
D. L. Matthews ◽  
C. O. Grogan ◽  
C. E. Manchester
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Recessive Gene ◽  
Gene Symbol ◽  
Chromosome 3

SUMMARYA new mutant in maize with an unusual ear location is described. The condition was found to be controlled by a simple recessive gene located near the breakpoint on chromosome 3. The gene symbol, te, is proposed.

scholarly journals Development of a New Maize (Zea mays L.) Breeding Program

2002 ◽  
pp. 25-30
Author(s):  
Pál Pepó ◽  
Szilárd Tóth
Keyword(s):  
Zea Mays ◽  
Recurrent Selection ◽  
Zea Mays L ◽  
Genetic Manipulation ◽  
Dominant Gene ◽  
Breeding Program ◽  
Regeneration Ability ◽  
Breeding Programs

Genetic manipulation may not replace any conventional method in crop breeding programs, but it can be an important adjunct to them. Plant regeneration via tissue culture is becoming increasingly more common in monocots such as corn (Zea mays L.). In vitro culturability and regeneration ability of corn decreased as homozigosity increased, which suggested that these two attributes were controlled primarily by dominant gene action. Pollen (gametophytic) selection for resistance to aflatoxin in corn can greatly facilitate recurrent selection and screening of germplasm for resistance at a much less cost and shorter time than field testing. Integration of in vivo and in vitro techniques in maize breeding program has been developed to obtain desirable agronomic attributes, speed up the breeding process and enhance the genes responsible for them. The efficiency of anther and tissue cultures in most cereals such as maize and wheat have reached the stage where it can be used in breeding programs to some extent and many new cultivars produced by genetic manipulation have now reached the market.

scholarly journals Ear Quality in Three Sweet Corn Populations Selected for Resistance to Common Rust

1999 ◽  
Vol 124 (6) ◽  
pp. 641-643
Author(s):  
Bruce G. Abedon ◽  
William F. Tracy
Keyword(s):  
Zea Mays ◽  
Rust Resistance ◽  
Recurrent Selection ◽  
Sweet Corn ◽  
Environment Interaction ◽  
Quality Traits ◽  
Kernel Size ◽  
Puccinia Sorghi ◽  
Phenotypic Recurrent Selection ◽  
Selection For

Research was conducted to evaluate correlated effects of full-sib phenotypic recurrent selection for resistance to common rust (Puccinia sorghi Schw.) on ear quality traits in three sugary1 (su1) sweet corn (Zea mays L.) populations: Minn11, Minn14, and NECDR. Cycles 0, 1, 2, and 3 of each population were evaluated in both rust infested and nonrust infested environments. Generally, selection for rust resistance resulted in significant, but minor, decreases in ear and kernel size. Changes in specific traits varied with population. The nonsignificant cycle × environment interaction indicates similar responses occurred in all environments evaluated. Based on these results, selection for ear quality traits need not accompany selection for resistance to common rust if maintenance of ear quality is desired.

scholarly journals CAMBIO DE FECHA DE SIEMBRA DEL MAÍZ EN CULIACÁN, SINALOA, MÉXICO

2010 ◽  
Vol 33 (1) ◽  
pp. 61
Author(s):  
José L. Ramírez-Díaz ◽  
J. Jesús Wong-Pérez ◽  
José A. Ruiz-Corral ◽  
Margarito Chuela-Bonaparte
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Puccinia Sorghi

En el Estado de Sinaloa, México, son dinamicos los cambios en prácticas agrícolas, tipos de variedad y estrategias de mejoramiento genético del cultivo del maíz (Zea mays L.), lo que ha permitido que el rendimiento de grano se incrementara en 63 % durante el periodo 1991-1993. Al respecto, los agricultores han adelantado la fecha de siembra del ciclo otoño-invierno (O-I) en relación al periodo óptimo determinado en estudios previos. En el ciclo OI 2002-2003 se sembraron, en condiciones de riego, ocho híbridos comerciales en cinco fechas de siembra espaciadas cada 15 d, de noviembre 15 a enero 15. Se tomaron datos de rendimiento de grano, días a floración masculina y femenina, altura de planta y mazorca, porcentaje de acame de raíz y tallo, calificación de roya (Puccinia sorghi) y de mazorca, así como las temperaturas diarias máxima, mínima y media. Hubo diferencias (P ≤ 0.01) en rendimiento de grano entre fechas de siembra, híbridos y para la interacción fechas de siembra x híbridos. El rendimiento más alto (promedio de los ocho híbridos) se obtuvo en la siembra de noviembre 15, 32 d antes que la fecha recomendada para el ciclo 1990-1991 (Diciembre 17). Los híbridos de grano blanco ‘H-375’ y ‘H-438’ tuvieron el rendimiento de grano más alto (promedio de cinco fechas de siembra), y ‘P-31G98 Y’ el más bajo. Las diferencias en temperatura entre los ciclos agrícolas, especialmente la temperatura máxima diaria, fue el factor más importante para explicar la interacción fecha de siembra x híbrido.

DIFFERENTIAL RESPONSE OF MAIZE INBREDS TO BENTAZON AND OTHER HERBICIDES

1988 ◽  
Vol 68 (2) ◽  
pp. 501-507 ◽  
Author(s):  
A. A. FLEMING ◽  
P. A. BANKS ◽  
J. G. LEGG
Keyword(s):  
Zea Mays ◽  
Weed Control ◽  
Zea Mays L ◽  
Recessive Gene ◽  
Dry Weight ◽  
Maize Breeding ◽  
Plant Weight ◽  
Herbicide Treatments ◽  
Maize Inbreds ◽  
Carrier Volume

One field and two greenhouse experiments were conducted to determine the reaction of various maize (Zea mays L.) inbreds and single crosses to four herbicide treatments (atrazine, atrazine plus tridiphane, bentazon, metolachlor) relative to a nontreated control. All herbicides except metolachlor, which was used preemergence, were applied early postemergence with a nonphytotoxic crop oil at 1% carrier volume. Of significant importance is the discovery of maize susceptibility to bentazon and its inheritance. We suggest that the symbol, ben, be assigned to the recessive gene that causes this susceptibility. In the greenhouse, inbreds were more tolerant to atrazine and bentazon than other herbicide treatments. Tridiphane increased atrazine activity and reduced dry plant weight of inbreds on the average by 19%. None of the single crosses was significantly susceptible to atrazine. All inbreds and single crosses were sensitive to metolachlor in the greenhouse, as shown by the 49 and 35% reduction in dry weight, respectively. Information from these experiments can be useful in identifying sources of tolerance and susceptibility to the tested herbicides for programs in conventional maize breeding, weed control, and molecular engineering.Key words: Maize, bentazon, atrazine, tridiphane, metolachlor, inheritance

Kernel-weight effects and transmission of a partial trisome involving the long arm of chromosome 5 in maize

1983 ◽  
Vol 25 (4) ◽  
pp. 346-353 ◽  
Author(s):  
J. B. Beckett
Keyword(s):  
Zea Mays ◽  
Reciprocal Cross ◽  
Zea Mays L ◽  
Kernel Weight ◽  
Translocation Breakpoint ◽  
Crossing Over ◽  
Chromosome 5

Effects of trisomy for a portion of the long arm of chromosome 5 of maize (Zea mays L.) were explored by using the B5La element derived from the B–A translocation TB-5La. In one family, the B5La chromosome was transmitted through the egg to half of the offspring; in two other families, the rate of transmission was 44 and 46%, respectively. From the reciprocal cross, only 5.6% of the progeny carried B5La. The presence of the allele Pr (purple aleurone) on the partial trisome made it possible to study the effect of trisomy for a portion of the long arm of chromosome 5 on kernel weight. The trisegmental kernels averaged 11% lighter than their disomic sibs on seven ears and were of the same weight on one ear. It appears that the particular alleles of genes on B5La originally reduced kernel weight, but one variant, presumably acquired by crossing over, did not. Crossover products involving an exchange between the translocation breakpoint on B5La and the pr locus occurred at a rate of 8.3%.

The mode of inheritance of a type of dwarfism in common wheat

Genome ◽  
1989 ◽  
Vol 32 (5) ◽  
pp. 932-933 ◽  
Author(s):  
D. R. Knott
Keyword(s):  
Triticum Aestivum ◽  
Stem Rust ◽  
Rust Resistance ◽  
Dominant Gene ◽  
Recessive Gene ◽  
Triticum Aestivum L ◽  
Stem Rust Resistance ◽  
Puccinia Graminis ◽  
Puccinia Graminis Tritici ◽  
Dark Green

A type of dwarfism found in crosses involving the wheat (Triticum aestivum L.) cultivar Webster and a stem rust (Puccinia graminis tritici Erik. &Henn.) susceptible line, LMPG, proved to be due to a dominant gene from cv. Webster and a recessive gene from LMPG. The dominant gene is closely linked to the gene Sr30, which conditions stem rust resistance in cv. Webster and is on chromosome 5D. The dwarf plants have short, dark green, stiff leaves and rarely develop more than two leaves before dying.Key words: dwarfism, Triticum aestivum, Puccinia graminis tritici, stem rust.

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