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1.
Spatial distribution of root activity and nitrogen fixation in sorghum/pigeonpea intercropping on an Indian Alfisol 总被引:2,自引:0,他引:2
Ito Osamu Matsunaga Ryoichi Tobita Satoshi Rao Theertham P. Devi Y. Gayatri 《Plant and Soil》1993,155(1):341-344
A medium-duration pigeonpea cultivar (ICP 1–6) and a hybrid sorghum (CSH 5) were grown on a shallow Alfisol in monocropping and intercropping systems. Using a monolith method, spatial distribution of nodulation, acetylene reduction activity (ARA) and root respiration were measured.The number, mass and ARA of nodules decreased exponentially with distance from the plant base except at the late reproductive stage. Nodulation and ARA tended to be higher in the intercrop than in the monocrop.Respiration rate of roots increased with distance from the plant base and reached a maximum value at about 20–30 cm. The rate was higher in pigeonpea than in sorghum and also higher in intercrop than in monocrop.This study suggests that pigeonpea roots are physiologically more active than sorghum roots, implying that pigeonpea may become a strong competitor for nutrients in the soil when intercropped. The nitrogen-fixing ability of pigeonpea may be enhanced by intercropping because the sorghum rapidly absorbed inorganic N which would otherwise inhibit N2 fixation. 相似文献
2.
Heterodera cajani is an important nematode pest of pigeonpea in India and a simple and reliable greenhouse procedure has been developed to screen pigeonpea genotypes for resistance to it. In pot experiments, white cysts of H. cajani were counted on the roots of the susceptible genotype ICPL 87 at 15, 30 and 45 days after seedling emergence in soils infested with different levels of H. cajani. The seedlings were rated for the number of white cysts per root system on a one (highly resistant, no cysts) to nine (highly susceptible, more than 30 cysts) scale. White cysts were not easy to see on wet roots but were clearly visible on slightly dried roots. Cyst counts and ratings were more uniform when roots of 30 day old seedlings were evaluated than when 15 or 45 day old seedlings were examined. Effects of different H. cajani infestation levels on the ratings were not significant although the use of higher inoculum densities (16 to 27 eggs and juveniles/cm3 soil) was effective in reducing variability. This procedure was used to screen 60 pigeonpea genotypes and all of them were rated seven or nine. Ten accessions of Atylosia spp. and Rhynchosia spp. were rated three. 相似文献
3.
Genome‐wide dissection of AP2/ERF and HSP90 gene families in five legumes and expression profiles in chickpea and pigeonpea 下载免费PDF全文
4.
Regeneration of viable plants was obtained via organogenesis from mature embryonal axes explants of pigeonpea. Shoots were produced from the apical region of embryonal axes after 20 days of dark incubation on modified Murashige and Skoog (1962) medium containing 8.86 M benzylaminopurine (BAP) and 1.07 M -naphthalene acetic acid (NAA). When the explants were cultured under light-dark (16--8 hrs) conditions, shoots were initiated only after 65 days of culture initiation. The explants lost their ability to regenerate plantlets when they were cultured in continuous light. Regenerated shoots elongated either in the same medium or in MS basal medium. About 40% of the elongated shoots sequentially produced simple, bifoliate and finally trifoliate leaves instead of producing trifoliate leaves directly. The elongated shoots were rooted efficiently upon transferring them to half strength MS medium supplemented with 2.41 M indole-3-butyric acid (IBA). Rooted plantlets were successfully transferred to soil after hardening. 相似文献
5.
Urease of pigeonpea has been immobilized on polyethyleneimine-activated cotton cloth followed by cross-linking with dimethyl suberimidate. Optimum immobilization (56%) was obtained at a protein loading of 1.2mg/5×5cm2 cloth piece. The immobilized enzyme stored in 0.1M Tris/acetate buffer, pH6.5, at 4°C had a t1/2 of 70 days. There was practically no leaching of the enzyme from the immobilization matrix in 15 days. The immobilized enzyme was used 7 times at an interval of 24h between each use with 75% residual activity at the end of the period. Blood urea analysis was carried out with immobilized urease for some clinical samples. 相似文献
6.
Thidiazuron either alone or in combination with IAA induced high frequency shoot regeneration from primary leaf segments of
three pigeonpea cultivars. Transfer of the cultures to medium with reduced concentration of thidiazuron resulted in further
development of the shoots. The regenerated shoots were subsequently transferred to medium supplemented with BA, IAA and gibberellic
acid where 5-10% of the shoots elongated further. Rooting of shoots could be obtained on half strength MS medium supplemented
with NAA. Histological studies confirmed the mode of regeneration as shoot organogenesis.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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8.
M. J. Burns K. J. Edwards H. J. Newbury B. V. Ford‐Lloyd C. D. Baggott 《Molecular ecology resources》2001,1(4):283-285
Pigeonpea (Cajanus cajan) is an important subsistence crop in India where traditional landraces and improved hybrids are grown alongside each other. Gene flow may result in genetic erosion of these landraces and their wild relatives, whilst transgene escape from future genetically engineered varieties is another potential hazard. To assess the impact of these factors gene flow needs to be measured. A set of 10 simple sequence repeat markers have been developed, which exhibit polymorphism across a range of pigeonpea varieties. Use of these markers also offers an efficient system for the assessment of genetic diversity within populations of pigeonpea. 相似文献
9.
In pigeonpea (Cajanus cajan L.) shoot buds were induced when cotyledonary node explants were supplemented with benzylaminopurine (BAP; 2 mg dm–3). When 0.1 mg dm-3 BAP and 0.01 mg dm-3 naphtahalene acetic acid were supplemented to the medium, the 34 – 35 % of induced buds developed to microshoots. By supplementing amino acids like proline, glutamine, asparagine and L-cysteine, shoot bud development to microshoots was enhanced at least by two fold. Amongst the amino acids proline gave maximum number of microshoots per explant. With increase in concentration of amino acids, fresh mass increased but microshoot number decreased. Also methane evolution was increased by addition of amino acids, and also in medium containing more of its nitrogen in the form of ammonia. Increased evolution of methane was accompanied by reduction in evolution of ethylene, and enhancement of efficiency of microshoot development. 相似文献
10.
Quantifying below-ground nitrogen of legumes 总被引:2,自引:2,他引:0
Quantifying below-ground nitrogen (N) of legumes is fundamental to understanding their effects on soil mineral N fertility and on the N economies of following or companion crops in legume-based rotations. Methodologies based on 15N shoot-labelling with subsequent measurement of 15N in recovered plant parts (shoots and roots) and in the root-zone soil have proved promising. We report four glasshouse experiments with objectives to develop appropriate protocols for in situ
15N labelling of the four legumes, fababean (Vicia faba), chickpea (Cicer arietinum), mungbean (Vigna radiata) and pigeonpea (Cajanus cajan). Treatments included 15N-urea concentration (0.1–2.0% w/w), feeding technique (leaf-flap and petiole), leaflet/petiole position (top and bottom of shoot) and frequency of feeding (one and two occasions). 15N-labelling via the leaf-flap was best for fababean, mungbean and pigeonpea, whilst petiole feeding was best for chickpea, in all cases at the lower-stem nodes 3 or 4 using 0.2 mL volumes of 0.5% urea (98 atom% 15N excess). Fed leaflets and petioles were removed within 2 weeks of labelling. Uneven 15N enrichment of the nodulated roots because of effects of the less-enriched nodules meant that root derived N in soil would be overestimated if recovered roots were more heavily nodulated than unrecovered roots. One possible solution would be to assume crown nodulation of the plants. Thus, recovered roots would be nodulated; root-derived N remaining in soil may be without nodules. The ratios of nodulated root to unnodulated root enrichments could then be used as an adjustment in the calculations, i.e. in the case of fababean and chickpea, by dividing calculated root-derived N in soil by 1.12 (fababean) and 1.56 (chickpea). 相似文献