scholarly journals GENETIC CONTROL OF MEIOSIS IN RICE, ORYZA SATIVA L. III. EFFECT OF DS GENES ON GENETIC RECOMBINATION

Genetics ◽  
1984 ◽  
Vol 108 (3) ◽  
pp. 697-706
Author(s):  
Kunio Kitada ◽  
Takeshi Omura
Keyword(s):  
Oryza Sativa ◽  
Chiasma Frequency ◽  
Genetic Recombination ◽  
Recombination Frequency ◽  
Oryza Sativa L ◽  
The Other ◽  
Crossing Over ◽  
Homozygous Condition ◽  
Synaptonemal Complexes ◽  
The Mean

ABSTRACT The recombination frequency as influenced by five independent recessive ds genes was measured on three segments of different chromosomes of rice, Oryza sativa L. Each ds gene in the homozygous condition resulted in an almost equally reduced recombination frequency in the three segments. When the mean reduction in recombination frequency was related to the reduction of chiasma frequency, the five ds genes were divided into two types: in one type the reduction of chiasma frequency almost corresponded to the mean reduction of recombination frequency, and in the other the chiasma frequency was greatly reduced in comparison with the mean reduction of recombination frequency. Three of the five ds genes were found to belong to the former group. In both types, normal synaptonemal complexes were observed in pachytene cells homozygous for ds genes. This finding suggests that ds genes do not affect the formation of synaptonemal complexes which are regarded as the prerequisite structure for crossing over.

Genetic control of meiosis in rice, Oryza sativa L. IV. Cytogenetical analyses of asynaptic mutants

1984 ◽  
Vol 26 (3) ◽  
pp. 264-271 ◽  
Author(s):  
Kunio Kitada ◽  
Takeshi Omura
Keyword(s):  
Oryza Sativa ◽  
Genetic Control ◽  
Chromosome Pairing ◽  
Chiasma Frequency ◽  
Oryza Sativa L ◽  
Recessive Gene ◽  
The Other ◽  
Normal Plant ◽  
Meiotic Stage ◽  
The Mean

One complete asynaptic mutant, MM-19, and two partial ones, MM-4 and MM-16, of Oryza sativa L. induced by N-methyl-N-nitrosourea (MNU) were cytogenetically investigated. No chromosome pairing occurred from zygotene to pachytene and 24 univalents appeared at diakinesis and metaphase 1 in MM-19. On the other hand, a partial lack of chromosome pairing was observed from zygotene to pachytene and various numbers of univalents occurred at metaphase I in MM-4 and MM-16. The mean chiasma frequency per bivalent as well as per cell decreased to different extents in MM-4 and MM-16, and the correlation between both the amount of chromosome pairing from zygotene to pachytene and the chiasma frequency per cell at diakinesis was recognized. Judging from the development of anthers in each meiotic stage, the duration of the stage forming the synizetic knot, at which chromosome pairing took place, was longer in MM-4 and MM-16 than in the normal plant, and was in MM-19 almost as long as in the normal plant. The results of gene analyses indicate that each of the three asynaptic mutants is controlled by a recessive gene and that, at least for MM-4 and MM-16, these genes are located at different loci.Key words: asynaptic, rice, Oryza, chiasma frequency, synizesis.

Equal frequencies of recombination nodules in both sexes of the pigeon suggest a basic difference with eutherian mammals

Genome ◽  
1999 ◽  
Vol 42 (2) ◽  
pp. 315-321 ◽  
Author(s):  
M I Pigozzi ◽  
A J Solari
Keyword(s):  
Linear Relationship ◽  
Genetic Recombination ◽  
Columba Livia ◽  
The Other ◽  
Crossing Over ◽  
Basic Difference ◽  
Autosomal Bivalents ◽  
Synaptonemal Complexes ◽  
Recombination Nodules ◽  
Chromatin Packing

The total number of recombination nodules (RNs) in the autosomal synaptonemal complexes (SCs) is statistically equivalent in oocytes and spermatocytes from the domestic pigeon Columba livia. The distribution on RNs along the three longest autosomes is also equivalent in oocytes and spermatocytes. The numbers of RNs show a linear relationship when plotted against SC length both in oocytes and spermatocytes. On the other hand, the ZW pair shows a single and strictly localized RN near the synaptic termini, but the ZZ pair shows unrestricted location of RNs (average 3.8). The ZW and ZZ pairs of the pigeon are euchromatic and do not show specific chromatin packing at pachytene in either sex. The lack of sex-specific differences in the number and location of RNs in the autosomal bivalents of C. livia and previous data on the chicken, suggest that the regulation of crossing-over is basically different in birds and mammals.Key words: meiosis, genetic recombination, recombination nodules, pigeon gametogenesis.

Efficacy of some insecticide modules against major insect pests and spider population of rice, Oryza sativa L.

ENTOMON ◽  
2018 ◽  
Vol 43 (4) ◽  
pp. 257-262
Author(s):  
Atanu Seni ◽  
Bhimasen Naik
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Untreated Control ◽  
Insect Pests ◽  
Oryza Sativa L ◽  
Gall Midge ◽  
Stem Borer ◽  
The Other ◽  
The Third ◽  
Treated Plot

Experiments were carried out to assess some insecticide modules against major insect pests of rice. Each module consists of a basal application of carbofuran 3G @ 1 kg a.i ha-1 at 20 DAT and Rynaxypyr 20 SC @ 30 g a.i ha-1 at 45 DAT except untreated control. All modules differ with each other only in third treatment which was applied in 65 DAT. The third treatment includes: Imidacloprid 17.8 SL @ 27 g a.i ha-1, Pymetrozine 50 WG @ 150 g a.i ha-1, Triflumezopyrim 106 SC @ 27 g a.i ha-1, Buprofezin 25 SC @ 250 g a.i ha-1; Glamore (Imidacloprid 40+Ethiprole 40% w/w) 80 WG @ 100 g a.i. ha-1, Thiacloprid 24 SC @ 60 g a.i ha-1, Azadirachtin 0.03 EC @ 8 g a.i ha-1, Dinotefuran 20 SG@ 40 g a.i ha-1 and untreated control. All the treated plots recorded significantly lower percent of dead heart, white ear- head caused by stem borer and silver shoot caused by gall midge. Module with Pymetrozine 50 WG @ 150 g a.i ha-1 treated plot recorded significantly higher per cent reduction of plant hoppers (>80% over untreated control) and produced higher grain yield (50.75 qha-1) than the other modules. Among the different treated modules the maximum number of spiders was found in Azadirachtin 0.03 EC @ 8 g a.i ha-1 treated module plot followed by other treatments.

Genetic Recombination in Coprinus

1970 ◽  
Vol 6 (3) ◽  
pp. 669-678
Author(s):  
B. C. LU
Keyword(s):  
Fruiting Body ◽  
Temperature Effects ◽  
Cold Shock ◽  
Genetic Recombination ◽  
Recombination Frequency ◽  
Temperature Treatment ◽  
Sensitive Period ◽  
Crossing Over ◽  
Synaptinemal Complex ◽  
Before And After

The frequency of genetic recombination in Coprinus lagopus may be modified by heat and cold shock. By removal of samples from a fruiting body before and after temperature treatment, it is possible to study the ultrastructure of chromosomes at the time recombination frequency (between den+ x +me-1) can be modified. The sensitive period for temperature effects and, therefore, probably the time of crossing over, commences with the formation of the synaptinemal complex (S.C.) and ends with its disappearance, i.e. during the entire existence of the S.C. It is concluded that recombination is an event subsequent to the formation of the S.C. and is independent of the process of its formation. It is suggested that the event takes place at the synaptic centre.

scholarly journals NaCl and Na2SO4 Salinities Have Different Impact on Photosynthesis and Yield-Related Parameters in Rice (Oryza sativa L.)

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 864
Author(s):  
Willy Irakoze ◽  
Hermann Prodjinoto ◽  
Séverin Nijimbere ◽  
Gervais Rufyikiri ◽  
Stanley Lutts
Keyword(s):  
Oryza Sativa ◽  
Oryza Sativa L ◽  
Net Photosynthesis ◽  
Maturity Stage ◽  
Comparative Effect ◽  
The Mean ◽  
Chloride Salinity ◽  
Nutrient Solutions ◽  
1000 Grain Weight ◽  
Intercellular Co2

To elucidate the comparative effect of chloride and sulfate salinities on photosynthesis and yield components in rice, plants of Oryza sativa (cv. I Kong Pao (salt-sensitive)) were exposed in nutrient solutions to 20 mM Na2SO4 or 40 mM NaCl (electrical conductivity of c.a. 4.30 dS m−1 for both solutions) from seedlings to maturity stage. Both types of salt induced a strong decrease in net photosynthesis (AN) at the seedling and tillering stages, while the intercellular CO2 concentrations (Ci) remained unaffected. Instantaneous transpiration (E) and stomatal conductance (gs) decreased at the tillering and seedling stages, respectively, only in plants exposed to NaCl. Chloride salinity also strongly decreased photosynthetic pigments, while no impact was detected in response to Na2SO4. All yield-related parameters were affected by salinities, but NaCl was significantly more deleterious than Na2SO4 for the mean number of tillers produced per plant, spikelets sterility and non-viable pollen percentage. In contrast, both types of salinity similarly impacted the percentage of fertile tillers and 1000-grain weight. At the grain level, more than 90% of toxic ions (Na+, excess of Cl− and S6+) accumulated in the hulls, thus preserving the internal part of the caryopses from toxic ion injuries.

scholarly journals Growth and Yield of Rice Plant by the Applications of River Sand, Coconut and Banana Coir in Ustic Endoaquert

2013 ◽  
Vol 18 (1) ◽  
pp. 25
Author(s):  
. Nurdin ◽  
Fauzan Zakaria
Keyword(s):  
Oryza Sativa ◽  
Similar Pattern ◽  
Yield Components ◽  
Rice Plant ◽  
Oryza Sativa L ◽  
Leaf Length ◽  
The Other ◽  
Growth And Yield ◽  
Rice Grain ◽  
River Sand

The research aimed to study effect the application of river sand (RS), coconut coir (CC), and banana coir (BC) on growth and yield of rice (Oryza sativa L.) in Ustic Endoaquert. The research was carried out in a green house using 3 × 3 × 3 factorial design. The RS factor consists of three treatment levels which were 0% RS, 25% RS, and 50% RS. Meanwhile, the CC and BC consist of three treatment levels, where each level were 0 Mg ha-1, 10 Mg ha-1 and 20 Mg ha-1. The results showed that RS, CC and BC applications did not have significant effect on plant height. On the other hand, all ameliorant applications had significantly increase leaf length and the highest percentage increasing was in BC (13.49%). The leaf numbers and tiller numbers had relatively similar pattern, except BC that had significantly increased leaf numbers by 77.69% and amount of tiller numbers by 49.45%. Furthermore, for yield components, RS, CC and BC applications had significant increased panicle numbers by 37.76%. It was only RS and BC that increased panicle lenght and the best increasing of 26.82% on RS. Meanwhile, the BC application only increased the rice grain numbers.[How to Cite: Nurdin and F Zakaria. 2013. Growth and Yield of Rice Plant by the Applications of River Sand, Coconut and Banana Coir in Ustic Endoaquert. J Trop Soils, 18 (1): 25-32. doi: 10.5400/jts.2013.18.1.25][Permalink/DOI:www.dx.doi.org/10.5400/jts.2013.18.1.25]

scholarly journals RECOMBINATION IN THE VICINITY OF INSERTIONS OF TRANSPOSON Tn5 IN MYXOCOCCUS XANTHUS

Genetics ◽  
1983 ◽  
Vol 105 (2) ◽  
pp. 281-291
Author(s):  
Erica Sodergren ◽  
Yvonne Cheng ◽  
Leon Avery ◽  
Dale Kaiser
Keyword(s):  
Genetic Recombination ◽  
Recombination Frequency ◽  
Myxococcus Xanthus ◽  
Physical Distance ◽  
The Other ◽  
Restriction Map ◽  
Transposon Tn5 ◽  
Good Correspondence ◽  
Reciprocal Crosses ◽  
Two Measures

ABSTRACT To test genetic recombination in the vicinity of insertions of the transposon Tn5, crosses were performed by transduction between M. xanthus strains carrying different insertions of Tn5. One member of each pair carried resistance to kanamycin (Tn5-Km); the other carried resistance to tetracycline (Tn5-Tc). The distance between each pair of Tn5 insertions was also measured by restriction mapping. The physical distance corresponding to each recombination frequency was calculated from the transductional linkage and compared with distance on the restriction map. A good correspondence between the two measures of distance was obtained for a pair of Tn5 insertions near the cglB locus and for another pair near the mgl locus. Correspondence between the two measurements of distance, the observed allelic behavior of Tn5-Km and Tn5-Tc at the same locus and the finding of the same frequencies of recombinants in reciprocal crosses implied that recombination in the vicinity of Tn5 was normal.

THE RELATIONSHIP BETWEEN CHIASMATA AND CROSSING OVER IN TRITICUM AESTIVUM

Genetics ◽  
1973 ◽  
Vol 75 (2) ◽  
pp. 231-246
Author(s):  
T K Fu ◽  
E R Sears
Keyword(s):  
Chiasma Frequency ◽  
Rust Resistance ◽  
Genetic Recombination ◽  
Substantial Reduction ◽  
Leaf Rust Resistance ◽  
Crossing Over ◽  
Two Temperatures ◽  
Independent Behavior ◽  
The Relationship

ABSTRACT Telocentrics for the β arm of chromosome 4A and the long arm of 6B were used as cytological markers for the determination of chiasma frequency. In concomitant studies of recombination, terminal segments of rye and T. umbellulatum chromatin carrying Hp (Hairy peduncle) and Lr9 (Leaf-rust resistance), respectively, marked 4A and 6B. Two temperatures, 21° and 32°, were used for both the 4A and 6B experiments.—Only one chiasma was observed in each heteromorphic bivalent. Because there was a substantial reduction in pairing between diakinesis and metaphase I, all determinations of chiasma frequency were made at diakinesis. In the 21° experiments, agreement was good between genetic recombination and cytological prediction on the basis of the partial chiasmatypy hypothesis that each chiasma represents a crossover. At 32° both chiasma frequency and crossing over, but particularly the latter, were strongly reduced. The fewer crossovers than expected are explained in part by stickiness of chromosomes at the high temperature, sometimes resulting in adjacent chromosomes being wrongly scored as having a chiasma, and in part by premetaphase disjunction of some recombined bivalents and subsequent independent behavior of the two resulting univalents.—Male transmission of the 4A telocentric from the heteromorphic bivalent was unusually high: 51% at 21° and 31% at 32°.

THE EFFECTS OF SUPERNUMERARY CHROMATIN IN THREE SPECIES OF GRASSHOPPER

1974 ◽  
Vol 16 (2) ◽  
pp. 285-296 ◽  
Author(s):  
Gilbert L. Schroeter ◽  
Godfrey M. Hewitt
Keyword(s):  
Life Cycle ◽  
Chiasma Frequency ◽  
Genetic Material ◽  
B Chromosomes ◽  
Population Variability ◽  
The Other ◽  
Direct Effects ◽  
Apparent Effect ◽  
Other Hand ◽  
The Mean

The chiasma frequencies in males of three species of grasshopper with and without B-chromosomes and supernumerary segments were scored at diplotene. The partially heterochromatic B's found in some individuals of Chimarocephala pacifica pacifica have no effect on chiasma frequencies. On the other hand, heterochromatic supernumerary segments in Oedaleonotus phryneicus males significantly increase the mean chiasma frequencies over individuals without them but not the between-cell variances. In Camnula pellucida neither the mitotically unstable B's nor supernumerary segments have any apparent effect on chiasma.frequencies. The supernumerary elements in Chimarocephala pacifica and Camnula pellucida may, however, produce other effects during the life cycle These and previous observations suggest that polymorphism involving extra genetic material in grasshoppers can result in increased population variability via two different means: (1) by producing variation in chiasma frequency or (2) through direct effects in the individuals possessing it. The importance of such a mechanism for producing variation is discussed.

CHIASMA FREQUENCIES IN PRIMARY TRISOMICS OF PEARL MILLET

1976 ◽  
Vol 18 (1) ◽  
pp. 11-15 ◽  
Author(s):  
V. Manga
Keyword(s):  
Pearl Millet ◽  
Chiasma Frequency ◽  
The Other ◽  
Pennisetum Typhoides ◽  
Primary Trisomics ◽  
The Mean

Seven primary trisomics were obtained in the progeny of an autotriploid Pennisetum typhoides (Burm.) S. &H. The trisomics could be distinguished from the diploids and from one another morphologically and were designated Dwarf, Bush, Slender, Semidwarf, Purple, Robust and Pseudonormal. In Purple and Pseudonormal the mean chiasma frequencies were significantly higher than in the diploid sibs but in Dwarf the mean chiasma frequency was significantly lower. In the other trisomics the chiasma frequencies did not differ from the diploid sibs. The trivalent frequencies and configurations varied in the different trisomics and no correlation was noticed between the length of the chromosome and trivalent frequency but one was observed between trivalent frequency and chiasma frequency.

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