摘要:

The composition of the high-molecular weight (HMW) glutenin subunits of 13 wheat cultivars grown in the Western Cape was determined using Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (SDS-PAGE). The molecular weight of the different subunits was determined using standard proteins with known molecular weights. The Glu-1 quality score and the frequency of the subunits controlled by chromosomes 1A, 1B and 1D were calculated for the different cultivars. Ten different patterns of HMW glutenin subunits consisting of 4–5 protein bands were found. A total of 14 different HMW glutenin subunits were found, enabling most of the cultivars to be identified.

ISSN:0257-1862    

DOI:10.1080/02571862.1996.10634365

出版商:Taylor&Francis Group    

年代:1996

数据来源: Taylor

摘要:

A survey of the germination performance of some South African soya bean [Glycine max(L.) Merrill.] cultivars, produced at different localities, was conducted. Seeds were harvested from two early-maturing (Columbus and Crawford), two intermediate-maturing (Prima and Highveld Top), and two late-maturing cultivars (Ibis and Impala), from seven sites. The standard germination test was performed on all 42 seed lots. Germination performance was not linked to any particular maturity type or cultivar, but locality had a distinct effect. Germination of seeds of some seed lots harvested at Groblersdal and Potchefstroom was reduced, primarily due to the effect of seed-borne pathogens, which resulted in relatively large numbers of dead seeds. At Piet Retief, poor germination performance was inversely related to the large number of abnormal seedlings in the standard germination test, which was due to damaged seed coats. There were highly significant correlations between the number of dead seeds and the incidence of fungal infection, and between the number of abnormal seedlings and seed-coat damage. The predominant seed-borne pathogen was identified asFusarium equiseti, a fungus not previously reported as being present in South African soya bean seed.

ISSN:0257-1862    

DOI:10.1080/02571862.1996.10634366

出版商:Taylor&Francis Group    

年代:1996

数据来源: Taylor

摘要:

A pedogeomorphic study was made of the area immediately east of Phalaborwa underlain by granitic materials. Fifty-five soil profiles from nine transects were examined in detail to determine, among other things, the spatial variability of the soils and the hillslope properties and to assess the influence of climatic factors on the land-surface and soils. The investigation showed the main features of the hillslopes to be their basic similarity, as they are all relatively short and flatfish with a minimal curvature. The soils also exhibited a fair degree of uniformity, being generally fairly shallow and occurring in a catenary sequence with strongly structured soils on the foot-slopes. Since the generally subdued relief and the shallow soils reflect a moderate input of water (rainfall) it was possible to relate the pedogeomorphology of the area to the dry, subtropical climate.

ISSN:0257-1862    

DOI:10.1080/02571862.1996.10634367

出版商:Taylor&Francis Group    

年代:1996

数据来源: Taylor

摘要:

The aim of this study was to evaluate proline accumulation as an indicator of drought stress and drought tolerance in spring wheat cultivars (Triticum aestivumL.) grown in the Western Cape. Drought stress was induced in whole plants and leaf discs in two cultivars with known drought tolerance, namely, Gamtoos (drought tolerant) and S ST 66 (slightly drought sensitive), as well as in two cultivars with unknown drought tolerance, namely, Nantes and SST 44. To assess the effect of growth stage on the reaction of the cultivars to drought stress, stress was induced during pre-anthesis and also during anthesis. Proline accumulation in whole plants showed clear genotypical differences during pre-anthesis and, to a lesser extent, during anthesis. A positive correlation between the degree (onset and extent) of proline accumulation and drought tolerance was found for Gamtoos and SST 66. Proline accumulation patterns in leaf discs did not correlate with results obtained with whole plants.

ISSN:0257-1862    

DOI:10.1080/02571862.1996.10634368

出版商:Taylor&Francis Group    

年代:1996

数据来源: Taylor

摘要:

The dry matter (DM) yield, cellulase DM disappearance (CDMD) and herbage nitrogen (N) of sheep-grazed perennial ryegrass [Lolium perenne(L.)] during its establishment year was evaluated. Yield and quality were monitored under N applications ranging from 120 to 720 kg N ha−1a−1. Total (perennial ryegrass and weeds) and perennial ryegrass DM yields increased with increasing levels of N up to 480 kg ha−1a−1. Conversely, weed DM yields declined with increasing N up to 480 kg ha−1a−1. A logistic model predicting the response of perennial ryegrass DM yield to applied N also indicated little justification for applying N in excess of 500 kg ha−1a−1. Although CDMD and herbage N increased throughout the range of N applied, such increase was significant (P<0.05) only up to 480 kg ha−1a−1. In terms of yield and quality, there is little justification for applying N in excess of 480 kg ha−1a−1to perennial ryegrass during its establishment year.

ISSN:0257-1862    

DOI:10.1080/02571862.1996.10634369

出版商:Taylor&Francis Group    

年代:1996

数据来源: Taylor

摘要:

'n Veldproef is uitgevoer oor twee groeiseisoene (1993 en 1994) in die Oos-Vrystaat om te bepaal waiter opbrengsverskille daar bestaan tussen verskillende koringkultivars wat varieër in aluminium (Al) -verdraagsaamheid. Vier verskillende pH- en suurversadigingsvlakke is gebruikom nege koringkultivars se opbrengsverskille te kwantifiseer, en die indeling van kultivars volgens wortelkleurtoetsresultate in groepe van aluminium-verdraagsaamheid te bevestig onder veldtoestande. Die Al-verdraagsame, en Al-vatbare groepe soos ingedeel onder veldtoestande het 'n gemiddelde opbrengsverlaging van 20% en 57% onderskeidelik getoon by 'n pH (KCl) van 3.5–3.8 en persentasie suurversadiging (%SV) van 32.5–39.1% in vergelyking met 'n grondsuurheidsvlak van pH (KCl) 4.3–4 en %SV van 11.6–12.7%.

ISSN:0257-1862    

DOI:10.1080/02571862.1996.10634370

出版商:Taylor&Francis Group    

年代:1996

数据来源: Taylor

摘要:

'n Veldproef is uitgevoer in die Oos-Vrystaat om te bepaal of kultivars wat verskil in aluminium (Al)-verdraagsaamheid ook verskil in wortelontwikkeling by verskillende grondsuurheidsvlakke. Drie kultivars wat varleër in Al-verdraagsaamheid is by vier grondsuurheidsvlakke in 'n verdeelde-perseelontwerp getoets. Die twee Al-sensitiewe-kuitivars, SST 124 en Betta, het 'n laer wortellengte as Tugela (Al-verdraagsaam) by 'n pH (KCl) van 4.2 en laer en 'n persentasie suurversadiging (%SV) van 22.3% en hoër getoon. Die wortelmassa van die Al-sensitiewe-kultivars was eers op 'n pH van 3.9 en %SV van 39.6% betekenisvol laer as die van die Al-verdraagsame-kultivars. Hierdie wortelstudie wys daarop dat die Al-verdraagsame-kultivar op 'n beter wortelontwikkeling as die Al-sensitiewe-kultivars onder suurtoestande gedui het.

ISSN:0257-1862    

DOI:10.1080/02571862.1996.10634371

出版商:Taylor&Francis Group    

年代:1996

数据来源: Taylor