scholarly journals Allele Mining in Diverse Accessions of Urochloa and Megathyrsus spp. Tropical Grasses to Improve Forage Quality and Reduce Environmental Impact

2020 ◽  
Author(s):  
SJ Hanley ◽  
TK Pellny ◽  
JJ de Vega ◽  
V Castiblanco ◽  
J Arango ◽  
...  
Keyword(s):  
Environmental Impact ◽  
Lipid Content ◽  
Target Genes ◽  
Allelic Diversity ◽  
Forage Quality ◽  
Panicum Maximum ◽  
Allele Mining ◽  
High Confidence ◽  
Ploidy Levels ◽  
Tropical Grasses

AbstractThe C4 Urochloa spp (syn. Brachiaria) and Megathyrsus maximus (syn. Panicum maximum) are used as pasture for cattle across vast areas in tropical agriculture systems in Africa and South America. A key target for variety improvement is forage quality: enhanced digestibility could decrease amount of land required per unit production and enhanced lipid content could decrease methane emissions from cattle. For these traits, loss-of-function (LOF) alleles in known gene targets are predicted to improve them, making a reverse genetics approach of allele mining feasible. We studied allelic diversity of 20 target genes (11 for digestibility, 9 for lipid content) in 104 accessions selected to represent genetic diversity and ploidy levels of U. brizantha, U. decumbens, U. humidicola, U. ruziziensis and M. maximum. We used RNAseq and then bait-capture DNA-seq to improve gene models in a U. ruziziensis reference genome to assign polymorphisms with high confidence. We found 953 non-synonymous polymorphisms across all genes and accessions; within these, we identified 7 putative LOF alleles with high confidence, including ones in the non-redundant SDP1 and BAHD01 genes present in diploid and tetraploid accessions. These LOF alleles could respectively confer increased lipid content and digestibility if incorporated into a breeding programme.HighlightWe found gene variants in a collection of tropical grasses that could help reduce environmental impact of cattle production.

scholarly journals Phosphorus as a mitigator of the effects of water stress on the growth and photosynthetic capacity of tropical C4 grasses

2016 ◽  
Vol 38 (3) ◽  
pp. 363 ◽  
Author(s):  
Frank Akiyoshi Kuwahara ◽  
Gustavo Maia Souza ◽  
Kezia Aparecida Guidorizi ◽  
Ciniro Costa ◽  
Paulo Roberto de Lima Meirelles
Keyword(s):  
Water Stress ◽  
Crop Production ◽  
Photosynthetic Capacity ◽  
Panicum Maximum ◽  
P Deficiency ◽  
Tropical Grasses ◽  
Tropical Forage ◽  
Productive Potential ◽  
Urochloa Decumbens ◽  
Urochloa Brizantha

Water deficiency during the dry seasons influences the relationship between water and gas exchange in tropical grasses, reducing their productive potential. In addition, the phosphorus (P) deficiency Brazilian soils adds to the set of factors limiting crop production. In this context, the objective of this study was to evaluate the responses of different tropical forage species to phosphorus supplementation as mitigating the damage caused by water stress. Seeds of Urochloa brizantha cv. MG-4, Urochloa decumbens cv. Basilisk, Panicum maximum cv. Áries, Panicum maximum cv. Tanzânia and Paspalum atratum cv. Pojuca were germinated in pots containing 10 liters of red-yellow Acrisol type soil. Experiments were conducted by combining levels of phosphorus, 8,0 and 100,0 mg of P dm-3, with two irrigation regimes, 100 and 40% replacement of transpired water. The biometric parameters, photosynthetic capacity, leaf water potential and soil chemical characteristics were evaluated, and the data was submitted to analysis of variance (ANOVA, p < 0.05), and subsequently the means were compared using a Tukey test (p < 0.05). The results showed for tropical grasses grown under water stress, there is a clear mitigating effect of phosphorus supplementation, especially on the maintenance of biomass growth. 

scholarly journals Production of grazed tropical grasses in different agroecosystems in Puerto Rico. III. Semiarid

1969 ◽  
Vol 72 (2) ◽  
pp. 211-219
Author(s):  
Luis E. Tergas ◽  
Jaime Vélez-Santiago ◽  
Angel V. Méndez-cruz
Keyword(s):  
Puerto Rico ◽  
Rainy Season ◽  
Semiarid Region ◽  
First Year ◽  
Panicum Maximum ◽  
Forage Production ◽  
Tropical Grasses ◽  
Significant Difference ◽  
Second Year ◽  
Cynodon Nlemfuensis

A field experiment was conducted at the Lajas Experiment Substation in the semiarid region of Puerto Rico to evaluate the production and persistence of 8 tropical grasses, Cynodon nlemfuensis Star, C. dactylon Coastcross-1, C. plectostachyus Star, Panicum maximum USDA Pl291047, Makueni, Guinea and P. maximum USDA PI 259553, and the naturalized pasture Dichanthium annulatus pajon. Small plots were grazed at 3- to 5-week intervals for 2 years. P. maximum USDA PI 259553 and Makueni were highly productive in the semiarid,.region, as well as in previous experiments in humid regions in Puerto Rico. They are highly recommended for grazing trials. P. maximum Makueni and USDA PI 291047 were the most productive during the first year, although they were not significantly different (P=0.05) from P. maximum USDA PI 259553 and Common Guinea, and Cynodon plectyostachyus Star. The production of C. nlemluensis Star was similar to that of Dichanthium annulatus but higher than that of C. dactylon Coastcross-1 (P=0.05). The average production for all grasses declined at the beginning of the year, during the cool short days in February and March, 1983, without any significant difference (P=0.05) among species and cultivars. Production increased at the beginning of the rainy season, but it was low at the peak of the rainy season because of trampling in poorly aerated and compact soils. C. plectostachyus Star was the most productive grass during the second year of experiment, although it was not significantly different (P=0.05) from P. maximum USDA PI 291017 and 259553 and cultivar Makueni. The production of Common Guinea and that of D. annulatus were. similar and higher than that of C. nlemfuensis Star and C. dactylon Coastcross-1 (P=0.05), which did not persist at the end of the experiment. Forage production during the second year was lower than in the first year because of less rainfall in 1983. The mean CP content of all grasses varied from 11.29 to 14.05, except that of D. annulatus, which was only 9.73%. CP content was lower during the periods of maximum forage production.

scholarly journals Production of grazed tropical grasses in different agroecosystems in Puerto Rico. II. humid northern coastal plains

1969 ◽  
Vol 72 (2) ◽  
pp. 201-210
Author(s):  
Luis E. Tergas ◽  
Jaime Vélez-Santiago ◽  
Doralissa Vera de Saldaña
Keyword(s):  
Puerto Rico ◽  
Crude Protein ◽  
Relative Difference ◽  
Panicum Maximum ◽  
Coastal Plains ◽  
Crude Protein Content ◽  
Rainfall Distribution ◽  
Tropical Grasses ◽  
Average Production ◽  
Humid Region

A field experiment was conducted near Barceloneta in the humid northern coastal plains of Puerto Rico to evaluate the production and persistence of 10 tropical grasses: Cynodon sp. local, Digitaria pentzii Slenderstem, C. nlemfuensis Star, C. plectostachyus Star, C. dactylon Coastcross-1, D. milanjiana Pangola Soto, Panicum maximum Guinea, P. maximum Guinea USDA PI 259553, P. maximum Makueni and D. decumbens Transvala grazed at 3- to 5-week intervals for one and a half year. P. maximum USDA PI 259553 was the most productive grass, but during the 13 grazings in 1981-1982, it was not significantly different (P=0.05) from C. plectostachyus Star; Cynodon sp. Local, D. pentzii Slenderstem, C. nlemfuensis Star, P. maximum Makueni, and D. decumbens Transvala. Guinea and D. milanjiana Pangola Soto were the least productive (P=0.05). Results for 7 grazings from January to June 1983 again showed P. maximum USDA PI 259553 to be the most productive grass, although not significantly different (P=0.05) from D. decumbens Transvala, C. dactylon Coastcross-1 and D. pentzii. The production of P. maximum Makueni and C. plectostachyus Star was intermediate; C. nlemfuensis Star and Guinea were the least productive, and D. milanjiana Pangola Soto did not persist under intensive grazing (P=0.05). The total mean production of all grasses of 0.92 and 1.00 ton/ha/grazing, respectively, were related to rainfall distribution. The general mean in crude protein content of forage was higher during the drier months. Average production of all grasses in this experiment was lower than in a similar experiment at Corozal in the humid region of Puerto Rico, the relative difference varied among cultivars.

Temperature influences on the growth, digestibility, and carbohydrate compositions of two tropical grasses, Panicum maximum var Trichoglume and Setaria sphacelata, and two cultivars of the temperate grass Lolium perenne

1971 ◽  
Vol 22 (4) ◽  
pp. 563 ◽  
Author(s):  
JR Wilson ◽  
CW Ford
Keyword(s):  
Lolium Perenne ◽  
Cold Water ◽  
Starch Content ◽  
Soluble Sugars ◽  
Water Soluble ◽  
Panicum Maximum ◽  
Lower Growth ◽  
Tropical Grasses ◽  
Structural Cell

Two tropical grasses, Panicunl maximum var. trichoglume and Setaria spliacelata cv. Nandi were compared with two cultivars of Lolium perenne, S.24 and Kangaroo Valley, grown in controlled environment at day/night temperatures of 15.6/10, 21 .1/15.6,26.7/21.1, and 32.2/26.7�C. The plants were harvested when still vegetative. The tropical grasses grew faster than the L. perenne cultivars at all but the lowest temperatures, and had a generally higher relative water content. The in vitro dry matter digestibility of the L. pereiine cultivars appeared inherently higher than that of the tropical grasses, but for each species digestibility Mtas modified by the environment and was highest at the lower growth temperatures. The tropical grasses were lower in alcohol- and cold water-soluble sugars, and higher in starch and structural (cell wall) carbohydrates than the L. perenne cultivars. For all grasses, as temperature increased from 15.6/10 to 26.7/21.1�C the concentration of the structural carbohydrates increased whilst that of the total non-structural carbohydrates changed relatively little. A further increase in temperature to 32.2/26.7� resulted in a marked decline in the concentration of simple sugars and structural carbohydrates whilst polymeric sugars increased. At this latter temperature the starch content in Setaria and Panicurn increased to as high as 16 and 13% of dry weight respectively. The differences in digestibility appeared to be associated with the differences in the proportions of the different carbohydrate fractions.

Response of some tropical grasses to molybdenum application

1978 ◽  
Vol 18 (94) ◽  
pp. 732 ◽  
Author(s):  
C Johansen
Keyword(s):  
The Other ◽  
Published Data ◽  
Panicum Maximum ◽  
Growth Responses ◽  
Cenchrus Ciliaris ◽  
Total N ◽  
Tropical Grasses ◽  
Tropical Legumes ◽  
Setaria Sphacelata ◽  
Large Growth

The response to Mo application of Panicum maximum var. trichoglume cv. Gatton (panic), Cenchrus ciliaris cv. Biloela (buffel) and Setaria sphacelata cv. Nandi (setaria) was studied at three rates of NO3 supply in pots containing soil that was severely Mo deficient for tropical legumes. There were no growth responses of these grasses to Mo, except for a marginally significant effect in panic at the highest NO3 treatment at the first harvest. These results are compared with Mo responses of legume/grass mixtures in the field and published data showing large growth responses of some temperate grasses to Mo. Application of Mo had no effect on total N concentrations of grass tops but markedly decreased NO3-N concentrations in buffel. Setaria had a greater ability to take up Mo than the other grasses and this was associated with the lower NO3 levels in this species. Critical Mo concentrations for growth of all grasses were below 0.02 p.p.m.

scholarly journals Experiment level curation identifies high confidence transcriptional regulatory interactions in neurodevelopment

2021 ◽  
Author(s):  
Eric Ching-Pan Chu ◽  
Alexander Morin ◽  
Tak Hou Calvin Chang ◽  
Tue Nguyen ◽  
Yi-Cheng Tsai ◽  
...  
Keyword(s):  
Nervous System ◽  
Experimental Evidence ◽  
Regulatory Networks ◽  
Large Scale ◽  
Target Genes ◽  
High Confidence ◽  
Transcriptional Regulatory Networks ◽  
Regulatory Interactions ◽  
Transcriptional Regulatory ◽  
Significant Enrichment

To facilitate the development of large-scale transcriptional regulatory networks (TRNs) that may enable in-silico analyses of disease mechanisms, a reliable catalogue of experimentally verified direct transcriptional regulatory interactions (DTRIs) is needed for training and validation. There has been a long history of using low-throughput experiments to validate single DTRIs. Therefore, we hypothesize that a reliable set of DTRIs could be produced by curating the published literature for such evidence. In our survey of previous curation efforts, we identified the lack of details about the quantity and the types of experimental evidence to be a major gap, despite the importance of such details for the identification of bona fide DTRIs. We developed a curation protocol to inspect the published literature for support of DTRIs at the experiment level, focusing on genes important to the development of the mammalian nervous system. We sought to record three types of low-throughput experiments: Transcription factor (TF) perturbation, TF-DNA binding, and TF-reporter assays. Using this protocol, we examined a total of 1,310 papers to assemble a collection of 1,499 unique DTRIs, involving 251 TFs and 825 target genes, many of which were not reported in any other DTRI resource. The majority of DTRIs (965, 64%) were supported by two or more types of experimental evidence and 27% were supported by all three. Of the DTRIs with all three types of evidence, 170 had been tested using primary tissues or cells and 44 had been tested directly in the central nervous system. We used our resource to document research biases among reports towards a small number of well-studied TFs. To demonstrate a use case for this resource, we compared our curation to a previously published high-throughput perturbation screen and found significant enrichment of the curated targets among genes differentially expressed in the developing brain in response to Pax6 deletion. This study demonstrates a proof-of-concept for the assembly of a high confidence DTRI resource in order to support the development of large-scale TRNs.

scholarly journals Storage and digestibility, voluntary intake and chemical components of hay of five tropical grasses

1969 ◽  
Vol 72 (4) ◽  
pp. 531-543
Author(s):  
Angel V. Méndez-Cruz ◽  
Norma Corchado-Juarbe ◽  
Víctor Siberio-Torres
Keyword(s):  
Dry Matter ◽  
Lignin Content ◽  
Neutral Detergent Fiber ◽  
Chemical Components ◽  
Panicum Maximum ◽  
Tropical Grasses ◽  
Harvest Intervals ◽  
The Mean ◽  
Voluntary Intake

An evaluation of the hay obtained from tropical grasses coastcross I (Cynodon dactylon), stargrass (Cynodon nlemfuensis), callie (Cynodon plectostachyus), slenderstem (Digitaria pentzii), and guinea (Panicum maximum) was made at three harvest intervals (35-, 45-, and 55-day) and four storage periods (γ than 4, 4 to 8, 8 to 12, and < than 12 months). In vivo dry matter digestibility and voluntary intake trials were performed with Holstein steers, weighing from 340 to 390 kg. Mean digestibility was 60.8%, 56.8% and 55.0%, respectively, for 35-, 45- and 55-day harvest intervals. The mean reduction caused by storage was from 60.8 to 50.6%, from 56.8 to 48.8%, and from 55.0 to 47.2% for the 35-, 45-, and 55-day intervals, respectively. The lower digestibility values were measured in callie. Voluntary intake declined 12, 18, and 17% and the digested dry matter voluntary intake declined from 1.47 to 1.1%, from 1.31 to 0.9%, and from 1.15 to 0.82%. Crude protein content decreased by 17.0, 15.4, and 15.6% for the respective intervals. The major detrimental effect in hay quality was observed after a 12-month storage. Plant maturity influenced the mean increase of neutral detergent fiber (NDF) from 69.7 to 72.6 and 76.6%, acid detergent fiber (ADF) from 37.9 to 43.4 and 47.7%; and lignin content, from 5.2 to 9.3% for the three growth intervals. This increase was 9, 16, and 42% for each parameter. However, as storage effect, NDF, ADF, and lignin content were raised by 4.3%, 12.3%, and 5.0%, respectively.

Establishment and persistence of perennial grass and herb cultivars and lines in a recharge area, North-West Slopes, New South Wales

2009 ◽  
Vol 60 (8) ◽  
pp. 753 ◽  
Author(s):  
S. P. Boschma ◽  
G. M. Lodge ◽  
S. Harden
Keyword(s):  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Perennial Grasses ◽  
Panicum Maximum ◽  
Comparative Performance ◽  
Rhodes Grass ◽  
Tropical Grasses ◽  
North West ◽  
Native Pasture ◽  
Plant Frequency

Two adjacent sites, one previously cropped and the other a native pasture, were sown with perennial temperate and tropical grasses and herbs (Expt 1), Phalaris aquatica (phalaris) and Festuca arundinacea (tall fescue) cultivars or lines (Expt 2), and perennial tropical grasses (Expt 3) near Manilla, NSW. Establishment, herbage mass and plant frequency were assessed in 2003–06 to (i) identify cultivars/lines with superior persistence, (ii) detect possible mechanisms required for successful production and persistence in a summer-dominant rainfall environment, and (iii) examine the comparative performance of the species groups when sown into previously cropped and native pasture areas. Plots were fertilised annually and grazed or mown at least seasonally. Most cultivars/lines persisted at the previously cropped site, while those on the native pasture site had to be resown and generally failed to persist beyond the first year. At the previously cropped site, summer-dormant tall fescue cv. Resolute MaxP® was the most persistent of the grasses evaluated in Expt 1. Grasses such as Lolium perenne cv. Avalon and Bromus stamineus cv. Gala did not perenneate, but regenerated annually from seed. Native grasses generally had poor establishment; however, Austrodanthonia richardsonii and A. fulva tended to increase in plant frequency over time. Chloris gayana (Rhodes grass) cv. Katambora and Panicum maximum (panic) cv. Gatton were the only tropical grasses that established in Expt 1, and both had plant frequencies similar (P > 0.05) to the temperate grasses at the final assessment. In Expt 2, Resolute MaxP again was the most persistent cultivar/line. Several experimental lines of phalaris (e.g. T39 and M225) had high herbage mass and good persistence compared with commercial cultivars. In Expt 3, Katambora Rhodes grass and Digitaria eriantha ssp. eriantha (digit grass) cv. Premier were the most persistent cultivars and had the highest herbage mass. These data highlighted summer dormancy in temperate grasses and frost tolerance in tropical grasses as two possible mechanisms important for persistence of grasses on the North-West Slopes of NSW and the risks associated with sowing perennial grasses into established native pastures.

Identification of Highly Polymorphic Molecular Markers and Potential Genotypes for Harnessing Chickpea Breeding Strategies

2020 ◽  
Author(s):  
Rajendra Kumar ◽  
Ashwani Kumar ◽  
Ashwani Yadav ◽  
Renu Yadav ◽  
J. P. Misra ◽  
...  
Keyword(s):  
Morphological Traits ◽  
Andhra Pradesh ◽  
Quantitative Traits ◽  
Crop Improvement ◽  
Allelic Diversity ◽  
Allele Mining ◽  
Efficient Utilization ◽  
Breeding Programs ◽  
Polymorphic Microsatellite ◽  
Stms Markers

Background: STMS markers and morphological traits were used to investigate the genetic relationship and allelic diversity in chickpea. In this study, we focused on the selection and more efficient utilization of core germplasm in breeding programs for chickpea crop improvement using STMS and quantitative / morphological traits. Methods: Seeds of elite accessions of chickpea were obtained from ICRISAT, Patancheru, Andhra Pradesh, India. 50 STMS markers and 11 quantitative traits were used for exploring the genetic variability and relationship in 35 chickpea accessions. Result: A total of 97 alleles were produced out of the 32 polymorphic STMS loci with an average of 3.03 alleles per locus ranging between 2-6 alleles per primer. The PIC value ranged from 0.029 to 0.768 with an average of 0.502. PIC value showed a highly positive correlation (r = 0.718) with number of alleles at the STMS loci. In both molecular and morphological markers / traits-based clustering, out of 35 chickpea accessions only one accession ICC-13892 was isolated at the end of clustering. The results indicated that highly polymorphic microsatellite markers NCPGR 68, NCPGR 50, NCPGR 81, NCPGR 48 and NCPGR 77 along with the accessions ICC-13892 having distant associations with ICC-13816, ICC-15697, ICC-15610, ICC-15868, ICC-15888, ICC-15996 with novel findings should be useful resources for strategies of allele mining, association genetics, mapping and cloning of gene(s) and in applied breeding to broaden the genetic base of chickpea.

Production of grazed tropical grasses in different agroecosystems in Puerto Rico: I. Humid mountain

1969 ◽  
Vol 72 (1) ◽  
pp. 99-108
Author(s):  
Luis E. Tergas ◽  
Jaime Vélez-Santiago ◽  
Doralisa Vera de Saldaña
Keyword(s):  
Puerto Rico ◽  
Crude Protein ◽  
Cynodon Dactylon ◽  
First Year ◽  
Panicum Maximum ◽  
Crude Protein Content ◽  
Forage Production ◽  
Tropical Grasses ◽  
Grazing Period ◽  
Second Year

A field experiment was conducted at the Corozal Experiment Substation in the humid mountain region of Puerto Rico to evaluate the production and persistence of tropical grasses, Brachiaria humidicula, Cynodon dactylon cv. Bermuda, C. nlemfuensis var. nlemfuensis cv. Star, Digitaria pentzii cv. Slenderstem, D. decumbens cv. Transvala, C. plectostachyus cv. Star and Panicum maximum cv. Makueni in small plots grazed at 5- to 7-week intervals for 2 years. P. maximum cv. Makueni was the most productive grass the first year, with a mean of 1.71 ton/ha dry forage per grazing period, but it was not statistically different (P = 0.05) from B. humidicola and C. dactylon cv. Bermuda. D. pentzii was the least productive. Production of all grasses, except P. maximum cv. Makueni, decreased during the short cool days in December and January. B. humidicola was the most productive grass the second year, with a mean of 1.73 ton/ha of dry forage, followed very closely by P. maximum cv. Makueni. Again D. pentzii cv. Slenderstem was one of the least productive, and C. nlemfuensis did not persist. Mean production of all grasses decreased during the drier periods; however, the crude protein content was higher. Total annual forage production was similar in both years, with means of 15.8 and 15.1 ton/ha dry forage, but much lower than the reported yields of these cultivars under cutting management in Puerto Rico.

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