scholarly journals Relationship between panicle differentiation and main stem leaf number in rice genotypes and red rice biotypes

2009 ◽  
Vol 66 (2) ◽  
pp. 195-203 ◽  
Author(s):  
Nereu Augusto Streck ◽  
Isabel Lago ◽  
Leosane Cristina Bosco ◽  
Gizelli Moiano de Paula ◽  
Felipe Brendler Oliveira ◽  
...  
Keyword(s):  
Oryza Sativa L ◽  
Flag Leaf ◽  
Daily Basis ◽  
Main Stem ◽  
Leaf Number ◽  
Red Rice ◽  
Cultivated Rice ◽  
Sowing Dates ◽  
Number Of Leaves ◽  
Rice Genotypes

Panicle differentiation (DP) is a key developmental stage in rice (Oryza sativa L.) because at this stage plant switches from vegetative to reproductive development and source-sink relation changes to allocate part of the photoassimilates for growing spikelets and kernels. The objective of this study was to determine the main stem Haun Stage (HS) and the number of leaves that still have to emerge until flag leaf at PD in several cultivated rice genotypes and red rice biotypes in different sowing dates. A two-year field experiment was conducted in Santa Maria, Rio Grande do Sul State, Brazil, during the 2005-2006 and 2006-2007 growing seasons, and three sowing dates each year. Nine cultivated rice genotypes and two red rice biotypes were used. PD was identified as the R1 stage of the COUNCE scale, by sampling four plants from each genotype on a daily basis. When 50% of the sampled plants were at R1, the main stem HS was measured in 20 plants per genotype. The main stem final leaf number (FLN) was measured in these 20 plants when the collar of the flag leaf was visible. HS at PD is related to FLN in many cultivated rice genotypes and red rice biotypes, and that at PD, the number of leaves still to emerge until flag leaf is not constant for all the rice genotypes. These findings are not in agreement with reports in the literature.

Red Rice (Oryza sativa) Biology. I. Characterization of Red Rice Ecotypes

1999 ◽  
Vol 13 (1) ◽  
pp. 12-18 ◽  
Author(s):  
José A. Noldin ◽  
James M. Chandler ◽  
Garry N. McCauley
Keyword(s):  
Flag Leaf ◽  
Natural Hybridization ◽  
Rice Cultivars ◽  
Red Rice ◽  
Cultivated Rice ◽  
Seed Shattering ◽  
Seed Moisture ◽  
Biology I ◽  
Plant Characteristics

Plant characteristics of red rice ecotypes obtained from Arkansas, Louisiana, Mississippi, and Texas, including 11 strawhulled, five blackhulled, two goldhulled, and one brownhulled type, were evaluated under field conditions. Most ecotypes were uniform and stable but manifested considerable genetic variability. Red rice plants had pubescent leaves, were taller with lighter green color, and produced more tillers and panicles per plant than rice cultivars ‘Lemont,’ ‘Mars,’ and ‘Maybelle.’ Most ecotypes were highly susceptible to seed shattering starting about 14 d after anthesis when seed moisture was more than 25%. Seeds of most ecotypes were highly dormant at harvest. Rice cultivars had a larger flag leaf and more total leaf area per plant at anthesis and produced more seeds per panicle than red rice. Some red rice ecotypes had plant characteristics closely related to cultivated rice suggesting natural hybridization with rice.

Gene flow from weedy red rice (Oryza sativa L.) to cultivated rice and fitness of hybrids

2009 ◽  
Vol 65 (10) ◽  
pp. 1124-1129 ◽  
Author(s):  
Vinod K Shivrain ◽  
Nilda R Burgos ◽  
David R Gealy ◽  
Marites A Sales ◽  
Kenneth L Smith
Keyword(s):  
Oryza Sativa ◽  
Gene Flow ◽  
Oryza Sativa L ◽  
Red Rice ◽  
Cultivated Rice ◽  
Weedy Red Rice

Effects of harvesting programme and sowing date on leaf growth in forage barley in Cyprus

1988 ◽  
Vol 110 (2) ◽  
pp. 353-366
Author(s):  
D. Wilman ◽  
D. N. Droushiotis
Keyword(s):  
Leaf Blade ◽  
Field Experiments ◽  
Leaf Growth ◽  
Main Stem ◽  
Available Nitrogen ◽  
Leaf Production ◽  
Primary Tiller ◽  
Sowing Dates ◽  
Number Of Leaves ◽  
Applied Nitrogen

SummaryAll combinations of four harvesting treatments and two sowing dates were compared in each of 2 years in field experiments near Nicosia. In one of the years, two levels of applied nitrogen were compared. The harvesting treatments were: (1) a milk-stage cut, (2) a boot-stage cut and a regrowth cut, (3) a grazing-stage cut and a regrowth cut, and (4) three grazing-stage cuts and a regrowth cut. The sowing dates were (1) normal (12 November) and (2) early (15 October), with sufficient irrigation to ensure establishment.Applied nitrogen had virtually no effect on leaf growth, evidently because of high reserves of available nitrogen in the soil. Early sowing increased the rates of leaf emergence, extension and expansion up to the time of the first ‘grazing’ cut (when the first node was showing) and reduced the number of leaves which died in that period. Where growth was uninterrupted to the milk stage, early sowing did not affect the number of leaves produced by a main stem or primary tiller, but increased the longevity of the later leaves. Where there were three ‘grazing’ cuts, early sowing allowed time for the production of more and larger leaf blades, with longer sheaths, between the third 'grazing’ cut and the final harvest.The ‘grazing’ cuts considerably reduced the rates of extension and expansion and the final size of the leaves which emerged soon after a cut. There was good recovery subsequently, however, in rates of extension and expansion and final leaf size, particularly with October sowing.During almost all the period of leaf production on a main stem or primary tiller, several leaves (up to six) were expanding at the same time. The stage, during the period between emergence and death, at which a leaf blade reached its full length was typically half-way between emergence and death. Where growth was uninterrupted, area per leaf blade was positively correlated with both the number of days between the emergence of successive leaves and the number of days between emergence and death.

scholarly journals Evaluation of Pre Released Rice (Oryza sativa L.) Genotypes under Different Sowing Dates in Rainy Season

2020 ◽  
pp. 77-84
Author(s):  
D. Anil ◽  
Sreedhar Siddi
Keyword(s):  
Field Experiments ◽  
Agricultural Research ◽  
Growth Parameters ◽  
Oryza Sativa L ◽  
Maximum Growth ◽  
Research Station ◽  
Pooled Data ◽  
Net Returns ◽  
Sowing Dates ◽  
Rice Genotypes

Field experiments were conducted to evaluate the pre released rice genotypes under different sowing windows on clay soils of agricultural research station, Kunaram, Telangana state, India during two consecutive rainy seasons of 2018 and 2019.The experiment was laid out in strip plot design with three replications. The treatments comprised of three sowing dates i.e. 20thJune, 5thJuly and 20thJuly in horizontal factor and four genotypes i.e. KNM 733, RNR 15048, KNM 1638 and KNM 118 in vertical factor. The pooled data results indicated that, among the genotypes the genotype KNM 1638 sown on 5th July recorded maximum growth parameters and highest grain yield (7455 kg ha-1) and followed by sown on 20th June. In respect of economics of treatment combinations, the highest net returns (Rs.75,326 ha-1), gross returns (Rs.1,35,326 ha-1) and B:C (2.26) ratio were obtained when rice crop was sown during 5th July with the  genotype KNM1638 and followed by sown on 20th June with the  genotype KNM 1638.

Prevalence, Agronomic Characteristics and Biology of Weedy Rice Biotypes of Nueva Ecija, Philippines

2014 ◽  
Vol 12 (1) ◽  
Author(s):  
EDWIN C. MARTIN
Keyword(s):  
Oryza Sativa L ◽  
Flag Leaf ◽  
Crop Protection ◽  
Dry Weight ◽  
Plant Ecology ◽  
Weedy Rice ◽  
Cultivated Rice ◽  
Potential Yield ◽  
Rice Varieties ◽  
Agronomic Characteristics

A survey of different weedy rice biotypes was conducted in rice field areasof Nueva Ecija from CY 2004-2006 to determine their prevalence, agronomiccharacteristics and biology. Surveys and quadrat samplings were conducted inrandom alongside of the roads to gather data on prevalence, height, numberof panicles/plant and density/m of weedy rice as well as the cultivated onesthey were associated. Studies on seed germination test, biology and agronomical characteristics of different weedy rice biotypes were also conducted at thelaboratory and screenhouse of Crop Protection Division, Philippine Rice ResearchInstitute.  Five weedy rice biotypes designated as WR-NE 1, WR-NE 2, WR-NE3, WR-NE 4 and WR-NE 5 were found distributed almost everywhere in ricefields of Nueva Ecija. Among the biotypes, WR-NE 1 was the most common inmany rice fields. Prevalence of all biotypes around the province ranged from 1to 17%. In the field, all biotypes were found taller but had fewer panicles plantthan cultivated rice varieties. In the laboratory, all weedy rice biotypes emergedearlier than PSB Rc82 and IR64. Under screenhouse condition, all weedy ricebiotypes were taller, produced more leaves and culms plant than the cultivatedrice. WR-NE 5 was the tallest biotype while WR-NE 1 and WR-NE 2 had themost number of leaves and culms plant-1-1. All biotypes matured earlier but hadno seed shattering characteristics. The biotypes had comparable values in termsof flag leaf areas and LAI/plant with PSB Rc82. Shoot dry weight and number ofpanicles/plant of all biotypes was significantly higher than the control varieties.WR-NE 4 and WR-NE 5 had the longest panicles, longer and wider grains.Grains/panicle was highest in WR-NE 5 (102 grains/panicle). Grain lengthwidthratio (GLWR)of all biotypes, however,weresignificantly lowerthan thetwocontrolvarieties.WR-NE1 and WR-NE4 had the longest length of awnwhileWR-NE4 and WR-NE5 had the highest grain weight(both at 24 g/1000grains).The growthand developmentof the fiveweedyrice biotypes weremuchadvantageouscomparedto selected cultivarssuggesting their competitivenessandthreatin achieving the potential yield and quality of harvestedcultivatedrice. Keywords - Plant ecology, prevalence, agronomic characteristics, weed biology, biotype,Oryza sativa L., weedy rice, experimental design, Philippines

scholarly journals Leaf development of cultivated rice and weedy red rice under elevated temperature scenarios

2013 ◽  
Vol 17 (2) ◽  
pp. 190-199 ◽  
Author(s):  
Nereu A. Streck ◽  
Lilian O. Uhlmann ◽  
Luana F. Gabriel
Keyword(s):  
Air Temperature ◽  
Leaf Development ◽  
Maximum Temperature ◽  
Climate Change Scenarios ◽  
Red Rice ◽  
Cultivated Rice ◽  
Daily Weather Data ◽  
Rice Genotypes ◽  
Leaf Appearance ◽  
Weedy Red Rice

The objective of this study was to simulate leaf development of cultivated rice genotypes and weedy red rice biotypes in climate change scenarios at Santa Maria, RS, Brazil. A leaf appearance (LAR) model adapted for rice was used to simulate the accumulated leaf number, represented by the Haun Stage, from crop emergence to flag leaf appearance (EM-FL). Three cultivated rice genotypes and two weedy red rice biotypes in six emergence dates were used. The LAR model was run for each emergence date using 100 years of synthetic daily weather data and six climate scenarios, including current, +1, +2, +3, +4 and +5 ºC increase in mean air temperature, with symmetric and asymmetric increase in daily minimum and maximum temperature. The increase in air temperature scenarios decreased the duration of the EM-FL phase in the earlier emergence dates (08/20, 09/20, 10/20) whereas in mid (11/20) and late emergence dates (12/20 and 01/20) the longest EM-FL phase was in the symmetric +5 ºC scenario and the shortest duration was in the asymmetric +3 and +4 ºC scenarios. The timing of the onset of flooding irrigation and nitrogen dressing may be altered if global warming takes place and weedy red rice has a potential to enhance its competitiveness with cultivated rice in future climates.

The Incidence and Effects of Hybridization between Cultivated Rice and its Related Weed Red Rice (Oryza sativa L.)

Evolution ◽  
1990 ◽  
Vol 44 (4) ◽  
pp. 1000 ◽  
Author(s):  
Susan A. Langevin ◽  
Keith Clay ◽  
James B. Grace
Keyword(s):  
Oryza Sativa ◽  
Oryza Sativa L ◽  
Red Rice ◽  
Cultivated Rice

Development of durum wheat and triticale cultivars as affected by thermo-photoperiodic conditions

2001 ◽  
Vol 52 (3) ◽  
pp. 387 ◽  
Author(s):  
Francesco Giunta ◽  
Rosella Motzo ◽  
Adriana Virdis
Keyword(s):  
Durum Wheat ◽  
Triticum Turgidum ◽  
Flag Leaf ◽  
Thermal Conditions ◽  
Sowing Date ◽  
Leaf Number ◽  
Stem Length ◽  
Sowing Dates ◽  
Leaf Appearance ◽  
Triticosecale Wittmack

The understanding of the interaction between thermo-photoperiodic conditions and the genetic control of anthesis date is fundamental in explaining the environmental adaptation of durum wheat and triticale cultivars. The development of 8 durum wheat (Triticum turgidum L. var. durum) and 2 triticale (×Triticosecale Wittmack) cultivars was studied at 3 sowing dates (September, November, and March) by observations on apex development, number and rate of leaf appearance, spike fertility, and number and length of elongated internodes. Variation in anthesis date was mostly explained by the total number of leaves, which ranged between 8.3 and 15, and hence by the duration of the phase of leaf primordium production. Total leaf number also affected the length ofthe subsequent phase until flag leaf appearance. The phyllochron was influenced by both sowing date and genotype, and was minimum in the March sowing (87 degree-days). The genotypic variability in phyllochron was due either to the variations in leaf number or to genotypic intrinsic differences. Time to terminal spikelet stage was related to the number of spikelets per spike and to the number of elongated internodes, although stem length depended more on internode length than on internode number. The number of spikelets per spike was associated with leaf number, but their relationship was affected by the thermal conditions during spikelet primordium initiation. No differences were observed between wheat and triticale cultivars, apart from the number of spikelets per spike.

scholarly journals Screening of rice (Oryza sativa L.) genotypes for shattering resistance

2021 ◽  
Vol 17 (1) ◽  
pp. 36-41
Author(s):  
Anju M. Job ◽  
S. Biju ◽  
B. Keerthyraj
Keyword(s):  
Seed Yield ◽  
Oryza Sativa L ◽  
Flag Leaf ◽  
Substantial Improvement ◽  
Plant Seed ◽  
Yield Attributes ◽  
Wide Variability ◽  
Rice Genotypes ◽  
Augmented Design ◽  
High Yielding Varieties

The present investigation on screening rice genotypes for shattering resistance was done involving twenty five rice genotypes. Among these lines Aiswarya and Aathira were taken as susceptible and resistant checks, respectively. Seeds were collected from Rice Research Stations of Kerala Agricultural University (KAU). Selected lines comprising both traditional and high yielding varieties were evaluated in augmented design and shattering was measured by Induced Random Impact (IRI) method using a force gauge apparatus. Fourteen characters were evaluated along with seed shattering and yield. Wide variability was found to exist among the tested genotypes for yield and most yield attributes. High phenotypic and genotypic co-efficient of variance (PCV and GCV) estimates were recorded for seed yield and shattering per cent indicating wide variability among genotypes for these traits and the possibility of improvement through selection. High heritability coupled with high genetic advance which indicate the influence of additive gene action in trait expression were observed for characters viz., days to fifty per cent flowering, length and width of flag leaf, number of panicles per plant, seed yield and shattering per cent. Substantial improvement in the expression of these characters over base population can be expected through simple selection.

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