Symbiotic nitrogen fixation and vegetative growth of cowpea (Vigna unguiculata (L.) walp.) in waterlogged conditions

1976 ◽  
Vol 45 (1) ◽  
pp. 113-127 ◽  
Author(s):  
F. R. Minchin ◽  
R. J. Summerfield
Keyword(s):  
Nitrogen Fixation ◽  
Vigna Unguiculata ◽  
Vegetative Growth ◽  
Symbiotic Nitrogen Fixation

Nitrogen Nutrition of Cowpea (Vigna unguiculata)

1977 ◽  
Vol 13 (3) ◽  
pp. 241-252 ◽  
Author(s):  
P. J. Dart ◽  
P. A. Huxley ◽  
A. R. J. Eaglesham ◽  
F. R. Minchin ◽  
R. J. Summerfield ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Vigna Unguiculata ◽  
Symbiotic Nitrogen Fixation ◽  
Nitrogen Nutrition ◽  
Combined Nitrogen ◽  
Nitrogen Treatments ◽  
Seed Yields ◽  
Applied Nitrogen

SUMMARYAverage seed yields of effectively nodulated cowpea plants were 38% greater than those of non-nodulated plants when both received applied nitrogen at concentrations ranging from 60 to 240 ppm during one of three periods: emergence to first flower, first flower to mid pod-fill, or mid pod-fill to maturity. Nodulation increased seed yields by 45% when plants received a ‘basal’ level of 30 ppm N throughout growth. None of the combined nitrogen treatments could compensate non-nodulated plants for the loss of symbiotic nitrogen fixation. Non-nodulated plants relying on applied N branched less, produced fewer peduncles and set fewer pods on each peduncle than nodulated plants.

scholarly journals Genome Editing in Cowpea Vigna unguiculata Using CRISPR-Cas9

2019 ◽  
Vol 20 (10) ◽  
pp. 2471 ◽  
Author(s):  
Jie Ji ◽  
Chunyang Zhang ◽  
Zhongfeng Sun ◽  
Longlong Wang ◽  
Deqiang Duanmu ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Genome Editing ◽  
Vigna Unguiculata ◽  
Symbiotic Nitrogen Fixation ◽  
Nodule Formation ◽  
Guide Rnas ◽  
Legume Crop ◽  
Receptor Like Kinase ◽  
Agronomical Traits

Cowpea (Vigna unguiculata) is widely cultivated across the world. Due to its symbiotic nitrogen fixation capability and many agronomically important traits, such as tolerance to low rainfall and low fertilization requirements, as well as its high nutrition and health benefits, cowpea is an important legume crop, especially in many semi-arid countries. However, research in Vigna unguiculata is dramatically hampered by the lack of mutant resources and efficient tools for gene inactivation in vivo. In this study, we used clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9). We applied the CRISPR/Cas9-mediated genome editing technology to efficiently disrupt the representative symbiotic nitrogen fixation (SNF) gene in Vigna unguiculata. Our customized guide RNAs (gRNAs) targeting symbiosis receptor-like kinase (SYMRK) achieved ~67% mutagenic efficiency in hairy-root-transformed plants, and nodule formation was completely blocked in the mutants with both alleles disrupted. Various types of mutations were observed near the PAM region of the respective gRNA. These results demonstrate the applicability of the CRISPR/Cas9 system in Vigna unguiculata, and therefore should significantly stimulate functional genomics analyses of many important agronomical traits in this unique crop legume.

Metabolite Regulation of Phosphenolpyruvate Carboxylase in Legume Root Nodules

1996 ◽  
Vol 23 (4) ◽  
pp. 413 ◽  
Author(s):  
KC Woo ◽  
S Xu
Keyword(s):  
Nitrogen Fixation ◽  
Glycine Max ◽  
Vigna Unguiculata ◽  
Symbiotic Nitrogen Fixation ◽  
Feedback Inhibition ◽  
Root Nodules ◽  
Psophocarpus Tetragonolobus ◽  
Glycine Max L ◽  
Fructose 1,6 Bisphosphate ◽  
Metabolite Regulation

The effects of metabolic activators and inhibitors on phosphoenolpyruvate carboxylase (PEPC) activity were examined at pH 7 in partially purified enzyme from nodules of soybean (Glycine max (L.) Merr.), Psophocarpus tetragonolobus DC. and Vigna unguiculata ssp. sesquipedalis (L.) Verdc. Glucose 6-phosphate, fructose 6-phosphate, glucose 1-phosphate, fructose 1-phosphate, fructose 1,6- bisphosphate and phosphoglycerate stimulated the activity about 2-fold at low (0.5 mM) but not saturating (2.5 mM) PEP concentration. Glc 6-P and fru 6-P were the most effective activators and they increased the affinity of the enzyme for PEP by 2-4-fold. The dicarboxylates, malate, succinate, malonate, 2-oxoglutarate and aspartate inhibited PEPC activity. Malate was the most inhibitory, and strongly inhibited PEPC activity even at saturating PEP concentration. The Ki values for malate were 0.3-0.4 mM for soybean and P. tetragonolobus. However, glc 6-P and fru 6-P alleviated maiate inhibition and increased the Ki values by 11- to 28-fold in these two species. We propose that glc 6-P (fru 6-P) activates PEPC in a feedforward regulation and protects it against feedback inhibition by malate and thus coordinates the supply of photosynthate availability with malate synthesis required by the bacteroids to support symbiotic nitrogen fixation in nodules.

Nodulation and symbiotic nitrogen fixation of cowpea (Vigna unguiculata (L.) Walp)

1987 ◽  
Vol 99 (2-3) ◽  
pp. 435-439 ◽  
Author(s):  
L. Senanayake ◽  
D. P. Knievel ◽  
S. E. Stevens
Keyword(s):  
Nitrogen Fixation ◽  
Vigna Unguiculata ◽  
Symbiotic Nitrogen Fixation

Nitrogen Nutrition of Cowpea (Vigna unguiculata). I. Effects of Applied Nitrogen and Symbiotic Nitrogen Fixation on Growth and Seed Yield

1977 ◽  
Vol 13 (2) ◽  
pp. 129-142 ◽  
Author(s):  
R. J. Summerfield ◽  
P. J. Dart ◽  
P. A. Huxley ◽  
A. R. J. Eaglesham ◽  
F. R. Minchin ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Seed Yield ◽  
Vigna Unguiculata ◽  
Symbiotic Nitrogen Fixation ◽  
Nitrogen Nutrition ◽  
Seed Yields ◽  
Applied Nitrogen

SUMMARYEffectively nodulated cowpea plants, grown in pots without applied nitrogen, were vegetatively equal to non-nodulated plants supplied with 60 ppm N throughout growth (88 days) and produced significantly greater seed yields. Supplying non-nodulated plants with 120 or 240 ppm N improved seed yields (but not significantly) compared with plants completely dependent on symbiotic fixation. Nodulation promoted branching, and improved pod set and/or retention compared with plants relying on applied N.

Farmers’ preference for improved grasses and legume forage species in six mixed farming system districts of southern region of Ethiopia

2017 ◽  
Vol 4 (2) ◽  
pp. 23-27
Author(s):  
Mergia Abera ◽  
Tekleyohannes Berhanu
Keyword(s):  
Vigna Unguiculata ◽  
Vegetative Growth ◽  
Farming System ◽  
Elephant Grass ◽  
Lablab Purpureus ◽  
Forage Legumes ◽  
Forage Crops ◽  
Forage Species ◽  
Herbage Yield ◽  
Chloris Gayana

Participatory on-farm evaluation of improved forage crops was conducted in six mixed farming system districts of Southern Ethiopia with the objective to identify farmers preferred forage crops (legumes and grasses). Two annual forage legumes (Vigna unguiculata L. (cow pea) and Lablab purpureus (L.), two perennial legumes (Medicago sativa (L.) (alfalfa) and Desmodium intortum (Mill.) Urb. (green-leaf)), and three perennial grasses (Chloris gayana Knuth (Rhodes grass) and two Pennisetum purpureum Schumach (elephant grass) accessions (No.16800 and 16798)) were evaluated in the study. The major farmers’ criteria considered in the evaluation of forage species were vegetative growth, herbage yield, tillering, protection of soil erosion, palatability, perfor- mance under dry weather conditions, performance in marginal area under low input management, multipurpose use (conservation and soil fertility) and fast growing condition. The study showed that elephant grass accession No. 16798, 16800 and Chloris gayana adapted well and farmers preferred them for their higher herbage yield, vegetative growth, tillering ability and drought resistance. Even though the annual forage legumes Lablab purpureus and Vigna unguiculata were superior in their forage yield, the farmers preferred the perennial forage legumes (Desmodium intortum and Medicago sativa) mainly for their performance under dry weather condi- tion due to their longer growth period. Therefore, the consideration of farmers’ preference for forage crops is crucial for increased adoption of improved forage crops in the region.

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