scholarly journals Reaction of cowpea (Vigna unguiculata) cultivars to Striga gesnerioides races from Mali and Niger

1998 ◽  
Vol 78 (3) ◽  
pp. 477-480 ◽  
Author(s):  
M. Touré ◽  
A. Olivier ◽  
B. R. Ntare ◽  
J. A. Lane ◽  
C. -A. St-Pierre
Keyword(s):  
Key Words ◽  
Vigna Unguiculata ◽  
Genetic Divergence ◽  
Laboratory Experiments ◽  
Varietal Resistance ◽  
Parasitic Weed ◽  
Striga Gesnerioides ◽  
Resistance Selection ◽  
Selection For

Field, pot and laboratory experiments were performed to evaluate the resistance of 12 cowpea (Vigna unguiculata [L.] Walp.) accessions to two races of the parasitic weed Striga gesnerioides (Willd.) Vatke (witchweed) from Cinzana, Mali and Maradi, Niger. Cultivar IT82D-849 showed resistance to either S. gesnerioides race in field, pot and laboratory experiments. IT81D-994 and Suvita-2 were both resistant to S. gesnerioides from Cinzana, but were susceptible to S. gesnerioides from Maradi. The occurrence of distinct varietal specificity among S. gesnerioides races may indicate the existence of significant interpopulation genetic divergence. These results highlight the possibility that varietal resistance could be overcome by some races of the parasitic weed, emphasizing the necessity to perform cowpea selection for resistance to various S. gesnerioides races. Key words: Cowpea, parasite races, resistance, selection, Striga gesnerioides, varietal specificity

scholarly journals The genome of cowpea (Vigna unguiculata [L.] Walp.)

2019 ◽  
Author(s):  
Stefano Lonardi ◽  
María Muñoz-Amatriaín ◽  
Qihua Liang ◽  
Shengqiang Shu ◽  
Steve I. Wanamaker ◽  
...  
Keyword(s):  
Vigna Unguiculata ◽  
Single Molecule ◽  
Warm Season ◽  
Multiple Organ ◽  
Sub Saharan Africa ◽  
Parasitic Weed ◽  
Nutritional Security ◽  
Striga Gesnerioides ◽  
Sub Saharan ◽  
Food And Nutritional Security

ABSTRACTCowpea (Vigna unguiculata [L.] Walp.) is a major crop for worldwide food and nutritional security, especially in sub-Saharan Africa, that is resilient to hot and drought-prone environments. A high-quality assembly of the single-haplotype inbred genome of cowpea IT97K-499-35 was developed by exploiting the synergies between single molecule real-time sequencing, optical and genetic mapping, and a novel assembly reconciliation algorithm. A total of 519 Mb is included in the assembled sequences. Nearly half of the assembled sequence is composed of repetitive elements, which are enriched within recombination-poor pericentromeric regions. A comparative analysis of these elements suggests that genome size differences between Vigna species are mainly attributable to changes in the amount of Gypsy retrotransposons. Conversely, genes are more abundant in more distal, high-recombination regions of the chromosomes; there appears to be more duplication of genes within the NBS-LRR and the SAUR-like auxin superfamilies compared to other warm-season legumes that have been sequenced. A surprising outcome of this study is the identification of a chromosomal inversion of 4.2 Mb among landraces and cultivars, which includes a gene that has been associated in other plants with interactions with the parasitic weed Striga gesnerioides. The genome sequence also facilitated the identification of a putative syntelog for multiple organ gigantism in legumes. A new numbering system has been adopted for cowpea chromosomes based on synteny with common bean (Phaseolus vulgaris).

Marker assisted selection for resistance to Striga gesnerioides in Cowpea (Vigna unguiculata L. Walp)

2017 ◽  
Vol 2 (5) ◽  
pp. 97-103 ◽  
Author(s):  
Victoria Larweh ◽  
◽  
Richard Akromah ◽  
Stephen Amoah ◽  
James Y. Asibuo ◽  
...  
Keyword(s):  
Vigna Unguiculata ◽  
Marker Assisted Selection ◽  
Striga Gesnerioides ◽  
Selection For

Le Striga gesnerioides et son hôte, le niébé : interaction et méthodes de lutte

2001 ◽  
Vol 79 (10) ◽  
pp. 1225-1240 ◽  
Author(s):  
Marie-Pier Dubé ◽  
Alain Olivier
Keyword(s):  
Vigna Unguiculata ◽  
Cultural Practices ◽  
Parasitic Weed ◽  
Vascular Connection ◽  
Striga Gesnerioides ◽  
Cowpea Cultivars ◽  
Legume Crop ◽  
Interaction Control ◽  
Intimate Association

Cowpea (Vigna unguiculata (L.) Walp.) is an important legume crop in subsaharian Africa. However, its cultivation is threatened by the parasitic weed Striga gesnerioides (Willd.) Vatke, which causes considerable yield losses. Striga gesnerioides is an obligate parasite with low photosynthetic activity. Its seeds germinate in response to specific germination stimulants exuded by host roots. After germination, an haustorium is formed through differentiation of the radicular apex. A vascular connection is subsequently established, allowing the parasitic weed to absorb water and nutrients that are essential for its development. Control of S. gesnerioides is difficult to achieve because of the intimate association between the parasitic weed and its host. The use of resistant cowpea cultivars, in combination with appropriate cultural practices, is probably the easiest and most effective method to control S. gesnerioides and achieve long term reduction of its seed bank in the soil.Key words: germination, interaction, control methods, cultivar resistance, Striga gesnerioides, Vigna unguiculata.

AC Nordic orchardgrass (Dactylis glomerata L.)

1993 ◽  
Vol 73 (3) ◽  
pp. 845-846 ◽  
Author(s):  
A. R. McElroy
Keyword(s):  
Key Words ◽  
Stem Rust ◽  
Dactylis Glomerata ◽  
Research Centre ◽  
Mass Selection ◽  
Puccinia Graminis ◽  
Plant Research ◽  
Selection For ◽  
Dactylis Glomerata L

AC Nordic is a late-maturing orchardgrass (Dactylis glomerata L.) cultivar. It was developed by mass selection for yield, persistence and resistance to stem rust (Puccinia graminis) at the Plant Research Centre, Agriculture Canada, Ottawa. Its yield was similar to that of cv. Sumas in a total of 33 station years in Quebec. Yield in second and subsequent production years was 101.6% of cv. Sumas over 19 station years. Key words: Dactylis glomerata L., orchardgrass

scholarly journals The Ecological Adaptive Significance Of Littoraria scabra For Their Survivorship In Extreme Mangrove Environment Of Tombariri

2018 ◽  
Vol 6 (2) ◽  
pp. 11
Author(s):  
Jans D Lalita ◽  
Jety K Rangan
Keyword(s):  
Key Words ◽  
High Tide ◽  
Adaptive Significance ◽  
Suitable Habitat ◽  
Population Abundance ◽  
Mangrove Environment ◽  
Selection For ◽  
Reproduction Activity

This research was found the ecological adaptive significance for their survivorship in mangrove microhabitat was as follow resting place, avoiding high tide, finding food, lying larvae, avoid sunshine, and hiding from predators. Significance of clumped distribution was taken to reduce drying stress, temperature, fallen from substrate against wave strikes, feeding and reproduction activity, suitable habitat. Significance of population abundance to balance strong predation and response to pressure of nature selection for their survivorship. Key Words : Littoraria scabra,  significance, ecology, survival, and mangrove ABSTRAKPenelitian ini menemukan bahwa signifikansi ekologi Littoraria scabra untuk survival di mikrohabitat mangrove Tombariri yang ekstrim adalah sebagai berikut berfungsi sebagai tempat istirahat, menghindari perendaman air, mencari makanan, meletakkan larva, menghindar cahaya dan bersembunyi dari predator-predator. Signifikansi L. scabra  distribusi spasial mengelompok untuk mereduksi stres kekeringan, suhu, terlepas di substrat akibat gelombang, aktivitas makan, reproduksi, kecocokan habitat. Signifikansi distibusi mengelompok dengan populasi tinggi untuk mengimbangi kuatnya predasi serta merespons tekanan seleksi alam yang kuat demi kelangsungan hidupnya. Kata Kunci : Littoraria scabra, signifikansi, ekologi, survival dan mangrove

Bruce birdsfoot trefoil

2008 ◽  
Vol 88 (6) ◽  
pp. 1093-1094
Author(s):  
Y. A. Papadopoulos ◽  
K. B. McRae ◽  
D. Gehl ◽  
S. A. E. Fillmore
Keyword(s):  
Nova Scotia ◽  
Root Growth ◽  
Key Words ◽  
Lotus Corniculatus ◽  
Birdsfoot Trefoil ◽  
Mass Selection ◽  
Plant Vigour ◽  
Growth Vigour ◽  
Cultivar Description ◽  
Selection For

Bruce birdsfoot trefoil (Lotus corniculatus L.) is a 71-clone synthetic variety developed at the Nappan Research Farm, Agriculture and Agri-Food Canada, Nappan, Nova Scotia. Bruce was developed through two cycles of mass selection for plant vigour (top and root growth) and winterhardiness, and one cycle of mass selection for re-growth vigour under grazing. In Atlantic Canada, Bruce produced more forage than the check cultivar Leo during 3 post-seeding years. It was also superior in spring growth with high first-cut herbage yields. Key words: Birdsfoot trefoil, Lotus corniculatus, cultivar description

Selecting for earliness and yield in sorghum at different sites

1991 ◽  
Vol 71 (1) ◽  
pp. 191-194 ◽  
Author(s):  
S. Plett ◽  
L. A. Nelson ◽  
M. D. Clegg
Keyword(s):  
Sorghum Bicolor ◽  
Key Words ◽  
Early Maturity ◽  
Early Maturing ◽  
Short Season ◽  
Selection For ◽  
Different Origins ◽  
Sorghum Bicolor L ◽  
Selection Of

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

Effect of index selection for reduced backfat thickness and increased growth rate on sow weight changes through two parities in swine

1992 ◽  
Vol 72 (2) ◽  
pp. 403-408 ◽  
Author(s):  
R. M. McKay
Keyword(s):  
Growth Rate ◽  
Key Words ◽  
Selection Pressure ◽  
Backfat Thickness ◽  
Index Selection ◽  
Weight Changes ◽  
Selection For ◽  
The Impact

The impact of continued selection for reduced backfat thickness and improved growth rate on weight changes in Yorkshire and Hampshire sows, from breeding as gilts to weaning their second litter, was studied. Results suggest that some sow weight changes may have been influenced by selection pressure exerted. Key words: Sows, Canadian Yorkshire, Hampshire, liveweight change

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