Selection for mating competence in Magnaporthe grisea pathogenic to rice

1991 ◽  
Vol 69 (10) ◽  
pp. 2130-2134 ◽  
Author(s):  
Chih-Cheng T. Chao ◽  
Albert H. Ellingboe

Sib selection for mating competence among isolates of Magnaporthe grisea that are pathogenic on rice has led to the selection of isolates where the mating type alleles are the only restriction on mating competence. Isolates are able to mate with all sibling isolates of opposite mating type and produce asci with ascospores. Isolates can function as male, female, or hermaphrodite in mating depending on the isolates with which they are mated. Mating competence is controlled by the genes in both mated isolates. Key words: mating competence, sib selection, rice blast, genetics.

1991 ◽  
Vol 71 (1) ◽  
pp. 191-194 ◽  
Author(s):  
S. Plett ◽  
L. A. Nelson ◽  
M. D. Clegg

Feasibility of selection of sorghum [Sorghum bicolor (L.) Moench] lines in a long–season environment for early maturity and yield was studied. Fifty-seven male lines from three different origins and F1 progenies produced by crossing the lines to three early-maturing female lines were used for these evaluations. Lines selected for yield had highest yield in a long-season environment but showed no yield advantage in short-season areas. There were lines from all three origins which should be useful in the locations tested. Selection for earliness and yield appeared feasible in a long season area. Key words: Heritability, correlation


1985 ◽  
Vol 27 (6) ◽  
pp. 697-704 ◽  
Author(s):  
Hei Leung ◽  
Paul H. Williams

Pyricularia oryzae (teleomorph: Magnaporthe grisea) parasitizes a variety of gramineous hosts and causes the rice blast disease worldwide. Through matings among P. oryzae isolates from rice, finger millet, and weeping lovegrass the inheritance of electrophoretic variants of six enzymes, phosphoglucomutase (PGM), phosphoglucose isomerase (PGI), glycerate-2-dehydrogenase (G2DH), malate dehydrogenase-3 (MDH-3), lactate dehydrogenase-1 (LDH-1), and lactate dehydrogenase-3 (LDH-3) was determined. All six variants were under single gene control as determined by tetrad and random spore analysis. However, at Ldh-3 and Mdh-3, there were consistent excesses of variant alleles among ascospore segregants. Preliminary data on the genetic control of hermaphroditism suggested that maleness in two Japanese rice isolates might be due to a single gene mutation. Linkage analyses among the six electrophoretic markers, mating type, and hermaphroditism suggested loose linkage between Pgm and G2dh with a recombination frequencies of 43.0%.Key words: linkage, Magnaporthe grisea, rice blast fungus.


Genetics ◽  
1995 ◽  
Vol 139 (4) ◽  
pp. 1495-1510 ◽  
Author(s):  
K S Weiler ◽  
L Szeto ◽  
J R Broach

Abstract Homothallic strains of Saccharomyces cerevisiae can convert mating type from a to alpha or alpha to a as often as every generation, by replacing genetic information specifying one mating type at the expressor locus, MAT, with information specifying the opposite mating type. The cryptic mating type information that is copied and inserted at MAT is contained in either of two loci, HML or HMR. The particular locus selected as donor during mating type interconversion is regulated by the allele expressed at MAT. MATa cells usually select HML, and MAT alpha cells usually select HMR, a process referred to as donor preference. To identify factors required for donor preference, we isolated and characterized a number of mutants that frequently selected the nonpreferred donor locus during mating type interconversion. Many of these mutants were found to harbor chromosome rearrangements or mutations at MAT or HML that interfered with the switching process. However, one mutant carried a recessive allele of CHL1, a gene previously shown to be required for efficient chromosome segregation during mitosis. Homothallic strains of yeast containing a null allele of CHL1 exhibited almost random selection of the donor locus in a MATa background but were normal in their ability to select HMR in a MAT alpha background. Our results indicate that Chl1p participates in the process of donor selection and are consistent with a model in which Chl1p helps establish an intrinsic bias in donor preference.


2005 ◽  
Vol 2 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Wang Bao-Hua ◽  
Lu Guo-Dong ◽  
Li Hai-Ming ◽  
Lin Yan ◽  
Wang Zong-Hua

AbstractAnalysis of mating type can provide an evaluation of the population genetic diversity of the rice blast fungus,Magnaporthe grisea. According to the sequences ofMAT1-1andMAT1-2genes of the fungus, two pairs of PCR primers specific to theMAT1-1andMAT1-2alleles were designed, and the PCR thermal profile was also optimized. To confirm its application in mating type assessment, 10 tester isolates were tested by PCR. The PCR amplification pattern of these tester isolates corresponded to their known mating type. Furthermore, 150 rice-field isolates from Fujian Province were mated with tester isolates GUY11 and KA3 side by side and also tested by PCR. Results showed that 95.1% of 123 fertile isolates were the same in mating type as determined by both PCR-amplified allele-specific fragments and mating with GUY11/KA3. Among 27 sterile isolates determined by GUY11 and KA3, seven wereMAT1-1and 20 wereMAT1-2as determined by PCR. This study indicates that PCR is applicable in assessingM. griseamating type and especially is capable of predicting the potential mating type of sterile isolates in the natural population of the fungus.


Genetics ◽  
1994 ◽  
Vol 138 (2) ◽  
pp. 289-296 ◽  
Author(s):  
S Kang ◽  
F G Chumley ◽  
B Valent

Abstract Using genomic subtraction, we isolated the mating-type genes (Mat1-1 and Mat1-2) of the rice blast fungus, Magnaporthe grisea. Transformation of M. grisea strains of one mating type with a linearized cosmid clone carrying the opposite mating-type gene resulted in many "dual maters," strains that contain both mating-type genes and successfully mate with Mat1-1 and Mat1-2 testers. Dual maters differed in the frequency of production of perithecia in pure culture. Ascospores isolated from these homothallic crosses were either Mat1-1 or Mat1-2, but there were no dual maters. Most conidia from dual maters also had one or the other of the mating-type genes, but not both. Thus, dual maters appear to lose one of the mating-type genes during vegetative growth. The incidence of self-mating in dual maters appears to depend on the co-occurrence of strains with each mating type in vegetative cultures. In rare transformants, the incoming sequences had replaced the resident mating-type gene. Nearly isogenic pairs produced from three M. grisea laboratory strains were mated to investigate their fertility. One transformant with switched mating type appears to have a mutation that impairs the development of asci when its mating partner has a similar genetic background. The M. grisea Mat1-1 and Mat1-2 genes are idiomorphs approximately 2.5 and 3.5 kb in length, respectively.


Methodology ◽  
2018 ◽  
Vol 14 (4) ◽  
pp. 177-188 ◽  
Author(s):  
Martin Schultze ◽  
Michael Eid

Abstract. In the construction of scales intended for the use in cross-cultural studies, the selection of items needs to be guided not only by traditional criteria of item quality, but has to take information about the measurement invariance of the scale into account. We present an approach to automated item selection which depicts the process as a combinatorial optimization problem and aims at finding a scale which fulfils predefined target criteria – such as measurement invariance across cultures. The search for an optimal solution is performed using an adaptation of the [Formula: see text] Ant System algorithm. The approach is illustrated using an application to item selection for a personality scale assuming measurement invariance across multiple countries.


2016 ◽  
Vol 11 (3) ◽  
pp. 217
Author(s):  
Estu Nugroho ◽  
Budi Setyono ◽  
Mochammad Su’eb ◽  
Tri Heru Prihadi

Program pemuliaan ikan mas varietas Punten dilakukan dengan seleksi individu terhadap karakter bobot ikan. Pembentukan populasi dasar untuk kegiatan seleksi dilakukan dengan memijahkan secara massal induk ikan mas yang terdiri atas 20 induk betina dan 21 induk jantan yang dikoleksi dari daerah Punten, Kepanjen (delapan betina dan enam jantan), Kediri (tujuh betina dan 12 jantan), Sragen (27 betina dan 10 jantan), dan Blitar (15 betina dan 11 jantan). Larva umur 10 hari dipelihara selama empat bulan. Selanjutnya dilakukan penjarangan sebesar 50% dan benih dipelihara selama 14 bulan untuk dilakukan seleksi dengan panduan hasil sampling 250 ekor individu setiap populasi. Seleksi terhadap calon induk dilakukan saat umur 18 bulan pada populasi jantan dan betina secara terpisah dengan memilih berdasarkan 10% bobot ikan yang terbaik. Calon induk yang terseleksi kemudian dipelihara hingga matang gonad, kemudian dipilih sebanyak 150 pasang dan dipijahkan secara massal. Didapatkan respons positif dari hasil seleksi berdasarkan bobot ikan, yaitu 49,89 g atau 3,66% (populasi ikan jantan) dan 168,47 g atau 11,43% (populasi ikan betina). Nilai heritabilitas untuk bobot ikan adalah 0,238 (jantan) dan 0,505 (betina).Punten carp breeding programs were carried out by individual selection for body weight trait. The base population for selection activities were conducted by mass breeding of parent consisted of 20 female and 21 male collected from area Punten, eight female and six male (Kepanjen), seven female and 12 male (Kediri), 27 female and 10 male (Sragen), 15 female and 11 male (Blitar). Larvae 10 days old reared for four moths. Then after spacing out 50% of total harvest, the offspring reared for 14 months for selection activity based on the sampling of 250 individual each population. Selection of broodstock candidates performed since 18 months age on male and female populations separately by selecting based on 10% of fish with best body weight. Candidates selected broodstocks were then maintained until mature. In oder to produce the next generation 150 pairs were sets and held for mass spawning. The results revealed that selection response were positive, 49.89 g (3.66%) for male and 168.47 (11.43%) for female. Heritability for body weight is 0.238 (male) and 0.505 (female).


Confectionery sunflower - a special area of use of sunflower, which requires the creation of marketable seeds quality features. One of the possible ways to create large-fruited sunflower is to create production hybrids and lines. Objective: to evaluate the created new large-fruited sunflower lines by a complex of morphological characters and determine the best lines for use as large-seeds hybrids as parent components or source material. In 2016-2019 years on the basis of the Institute of Oilseed Crops NAAS a study was conducted to assess the economic characteristics of large-fruited sunflower lines. We studied a collection of 27 lines of large-seeds sources. The lines were created by direct selection or crossing and sampling: Reyny of Argentinean origin, Zaporizhzhya confectionery variety, confectionery hybrid with striped pericarp color of Israeli origin, white seed of Turkish origin, synthetic population - donor of complex resistance. To study from the collection, lines were drawn that went through at least 7 generations with selection for seed size. Experience has shown that the shortest growing season for lines 174d and KP11 was 99 days, and the longest for lines I2K670 was 109 days. In the studied collection, the greatest mass of 1000 seeds has the KP11-146.47g line, which is the mother component and does not have branching. The second by weight of 1000 seeds (109 g) stood out line 168v, which also had branches and pollen fertility restoration genes and will be used as the paternal form. The third largest is also one basket line ZKN51-100. The collection included lines originating from the same combination, but with a different morphotype for the presence and absence of branching. So, based on the combination of KP11 x Zaporizhzhya Confectionery, three lines were obtained. A mass of 1000 seeds was observed in 98-86 g, with the branching line having the largest mass of 1000 seeds. The lines created with one combination VK678 x ZKN32: with a branch 168a had a mass of 1000 seeds 95g, and a line 168b - without a branch 109 g. Of the two lines obtained from the descendants of the combination KP11 x the striped hybrid both had branches, but the seeds were much smaller (weight of 1000 seeds 59 and 79 g). The collection also studied samples created on the basis of varieties and populations 160c, 174, 175b, the mass of 1000 seeds of which turned out to be more acceptable for large-fruited use from 83 to 99 g. Summing up the results of studying the collection of newly created lines, we can highlight the lines 162d, 168v, 175b, KP11 that are potentially promising for use in hybrids. The selections showed that large-fruited lines can be obtained from large-fruited varieties, self-pollination of large-fruited hybrids and crossing lines with hybrids and varieties. Self-pollination and selection of large-fruited lines in several generations does not provide the necessary variability for positive changes in selections. The result of the selection by weight of 1000 seeds in the offspring from crosses and from populations creates opportunities for new large-seeds sunflower.


Glycobiology ◽  
2021 ◽  
Author(s):  
Hannah M Stephen ◽  
Trevor M Adams ◽  
Lance Wells

Abstract Thousands of nuclear and cytosolic proteins are modified with a single β-N-acetylglucosamine on serine and threonine residues in mammals, a modification termed O-GlcNAc. This modification is essential for normal development and plays important roles in virtually all intracellular processes. Additionally, O-GlcNAc is involved in many disease states, including cancer, diabetes, and X-linked intellectual disability. Given the myriad of functions of the O-GlcNAc modification, it is therefore somewhat surprising that O-GlcNAc cycling is mediated by only two enzymes: the O-GlcNAc transferase (OGT), which adds O-GlcNAc, and the O-GlcNAcase (OGA), which removes it. A significant outstanding question in the O-GlcNAc field is how do only two enzymes mediate such an abundant and dynamic modification. In this review, we explore the current understanding of mechanisms for substrate selection for the O-GlcNAc cycling enzymes. These mechanisms include direct substrate interaction with specific domains of OGT or OGA, selection of interactors via partner proteins, posttranslational modification of OGT or OGA, nutrient sensing, and localization alteration. Altogether, current research paints a picture of an exquisitely regulated and complex system by which OGT and OGA select substrates. We also make recommendations for future work, toward the goal of identifying interaction mechanisms for specific substrates that may be able to be exploited for various research and medical treatment goals.


1975 ◽  
Vol 17 (3) ◽  
pp. 441-449 ◽  
Author(s):  
A. M. DeLange ◽  
A. J. F. Griffiths

In Neurospora crassa, strains of opposite mating type generally do not form stable heterokaryons because the mating type locus acts as a heterokaryon incompatibility locus. However, when one A and one a strain, having complementing auxotrophic mutants, are placed together on minimal medium, growth may occur, although the growth is generally slow. In this study, escape from such slow growth to that at a wild type or near-wild type rate was observed. The escaped cultures are stable heterokaryons, mostly having lost the mating type allele function from one component nucleus, so that the nuclear types are heterokaryon compatible. Either A or a mating type can be lost. This loss of function has been attributed to deletion since only one nuclear type could be recovered in all heterokaryons except one, but deletion spanning adjacent loci has been directly demonstrated in a minority of cases. Alternatively when one component strain is tol and the other tol+ (tol being a recessive mutant suppressing the heterokaryon incompatibility associated with mating type), escape may occur by the deletion or mutation of tol+, also resulting in heterokaryon compatibility. An induction mechanism for escape is speculated upon.


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