摘要:

The reliability of random amplified polymorphic DNA (RAPD) techniques to amplify polymorphisms in the asparagus (Asparagus officinallisL.) genome was investigated. DNA fragments generated by 10‐base primers were separated on 1.5% agarose or 8% polyacrylamide gels, and the sensitivity of ethidium bromide and silver staining of amplified DNA products analysed on these gels was compared. Resolution of DNA bands on polyacrylamide gels was superior to that on agarose gels. Silver staining was more sensitive than ethidium bromide staining. The gel type used to separate DNA bands, and the staining technique used influenced the number of bands visualised for each DNA profile generated. The six asparagus cultivars used in this study were distinguished by unique banding patterns generated by each primer. OPC‐12 for example generated polymorphic markers unique to three of the cultivars investigated. These markers were: ASP (500, 400, and 300 bp), TU (700 bp), and (PC 550 bp). Our investigation indicates that RAPD markers can be used to characterise asparagus cultivars, and that the technique is sensitive enough to reveal differences within seed‐raised commercial cultivars. RAPD technology has the potential to detect somaclonal variation occurring during micropropagation.

ISSN:0114-0671    

DOI:10.1080/01140671.1998.9514032

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Mortality responses of 3‐day‐old eggs and 1st, 3rd, and 5th instars of three leafroller (Lepidoptera: Tortricidae) pests, infesting kiwifruit (Actinidia deliciosa) after exposure to a high‐temperature controlled atmosphere (2% O2with 5% CO2at 40°C) were determined. All four life stages ofCnephasia jactatana(Walker) had similar mortality responses to controlled atmosphere (CA) treatment at the 99% mortality level. Fifth instars ofCtenopseustis obliquana(Walker) were more tolerant than the other three life stages tested.Epiphyas postvittana(Walker) showed a trend of increasing exposure time to achieve 99% mortality as development progressed.E. postvittanawas more tolerant of CA treatment thanC. obliquanaandC. jactatana. An exposure time of 6 h resulted in control (> 99% mortality) ofC. jactatanaandC. obliquanahowever, did not control all life stages ofE. postvittana. There is potential to combine a short high‐temperature CA treatment with a longer period of low‐temperature CA storage to control all three species.

ISSN:0114-0671    

DOI:10.1080/01140671.1998.9514033

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Eighty‐five accessions of 33 species ofAlliumwere screened for susceptibility to foliar bacterial soft rot caused byPseudomonas marginalis(Brown 1918) Stevens 1925 andP. viridiflava(Burkholder 1930) Dowson 1939. Plants grown in a greenhouse were wounded then co‐inoculated with cell suspensions ofP. marginalis and P. viridiflava. A. cepa’Pukekohe Longkeeper’ was highly susceptible to foliage soft rot. Mean disease scores (0 = no disease; 5 = severe soft rot) of the otherAlliumaccessions ranged from 0 (an accessionof A. sativum) to 4.9 (A.fistulosum’White Lisbon'). Statistically significant differences in mean disease scores were detected between accessions of individualAlliumspp. and between differentAlliumspp.

ISSN:0114-0671    

DOI:10.1080/01140671.1998.9514034

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Two shallot (Allium cepavar.ascalonicumL.) cultivars, ‘Mikor’ and ‘Jermor’, were used to test a protocol forin vitrovirus elimination. Basal explants were prepared, surface sterilised, and placed onto a medium consisting of Murashige and Skoog (M & S) salts and vitamins with the addition of 3% sucrose, 1.0 mg/litre benzyladenine, 50 mg/litre ribavirin, and 0.8% agar. The explants underwent 5–6 days of continuous heat therapy: 4 h light at 35°C; 4 h dark at 31°C. When the shoots were 2–3 cm long they were excised, transferred to shoot inducing medium without ribavirin (the anti‐viral chemical), and grown under normal tissue culture conditions of 24°C under fluorescent lights with a photoperiod of 16 h. Finally, the plantlets were introduced to a bulb inducing medium (M & S salts and vitamins, 120 g/litre sucrose, 5 g/litre activated charcoal) for 2 monthsin vitrobefore being tested for onion yellow dwarf and shallot latent viruses by ELISA (enzyme‐linked immunosorbent assay) and transferred either to the glasshouse or into long‐term storage (6°C with a photoperiod of 16 h). Virus assays have confirmed that 60% of resulting ‘Jermor’ and 62.0% of ‘Mikor’ grownin vitroplants were free of shallow latent and onion yellow dwarf virus infections.

ISSN:0114-0671    

DOI:10.1080/01140671.1998.9514035

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Rooted cuttings ofAcalypha hispaniolaewere grown in peat/composted bark (7: 3 v/v) medium for 4 months to evaluate their response to five levels of nitrogen (N), phosphorus (P), potassium (K), and lime. There was a linear response to added N with foliar dry matter increasing over the range 0–600 g N/m3and a leaf N content of c. 3.3% at this highest rate of N. Predicted maximum flower dry weight occurred at 400 g N/m3. P additions suppressed growth and flowering. Foliage P content needs to be held at c. 0.2%. Chlorosis of mature leaves was most severe with N deficiency but was also caused by P toxicity. Chlorosis in immature leaves was attributed to P‐induced iron deficiency and was most severe when the P: Fe ratio in the leaves was 62: 1. Liming reduced P toxicity and the lime rate for maximum growth was 6–9 kg/m3and a pH of c. 5. K additions had little effect on growth. A foliage K content of c. 2% is recommended.

ISSN:0114-0671    

DOI:10.1080/01140671.1998.9514036

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Oven drying is the accepted method for determining the dry matter content of kiwifruit (Actinidia deliciosa) and can be used as an indicator of harvest maturity and quality. The disadvantage of this method is the time taken to complete the test, typically overnight. Infrared drying of kiwifruit and apple pomace is shown to be an alternative, giving the same level of accuracy as oven drying but with a much reduced determination time. This method is also comparable in drying time to microwave drying, but with the advantage of continuous recording of drying progress, through to final dry weight.

ISSN:0114-0671    

DOI:10.1080/01140671.1998.9514037

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The total biotin level (free plus protein‐bound biotin) was measured in apple (Malus domesticaBorkh.) leaves of both an early maturing ‘Gala’ and a late maturing variety ‘Braeburn’. The biotin concentration increased linearly in apple leaves over the duration of the season, with both the final concentration and the rate of increase significantly greater in ‘Braeburn’. The concentrations ranged from 200–300 ng biotin/g (fresh leaf) during the leaf expansion phase to 600–800 ng biotin/g (fresh leaf) at senescence 10 months later. The calculated seasonal rates were 1.22 and 2.75 ng biotin/g (fresh leaf) per day for ‘Gala’ and ‘Braeburn’ respectively.

ISSN:0114-0671    

DOI:10.1080/01140671.1998.9514038

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Hydrogen cyanamide is used in areas with inadequate winter chilling to increase fertility and budbreak uniformity in many fruit tree species. This study examined the effect of hydrogen cyanamide (Dormex) on budbreak ofActinidia deliciosa’Hayward’ in relation to time of application and cane length. Treatment times were 8, 6, 4, and 2 weeks before expected budbreak. For each application time, 6‐, 12‐, or 18‐bud long canes were treated. Treatments were arranged in a complete randomised block design with five plants per treatment time. Canes treated 8 and 6 weeks before expected budbreak reached the advanced open cluster stage 15–35 days earlier than untreated canes. Cyanamide shortened the time‐lapse from bud swelling to cluster opening in all the treatments dates and increased cane fruitfulness by increasing the number of flowers per bud and per fruiting shoot. The earliest application enhanced budbreak but did not significantly increase the percentage of fruitful buds, whereas the percentage of flowering shoots in canes treated 2 weeks before expected budbreak was double than that of untreated canes, regardless the cane length. A significant interaction occured between cane length and treatment date. Untreated canes produced the largest shoots.

ISSN:0114-0671    

DOI:10.1080/01140671.1998.9514039

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Explants of jojoba (Simmondsia chinensis(Link) Schn.) from randomly selected plants were propagatedin vitro. On modified Murashige‐Skoog (MS) medium supplemented with 1 mg/litre BA (N6‐benzyl‐adenine) there was a 4.6‐fold increase in shoot numbers at 30 days. After 15 days on modified MS medium supplemented with 3 mg/litre IBA (indolebutyric acid) c. 25% of the shoots had developed roots. The best exflasking survival rate of the rooted plantlets (90%) was observed when the plantlets were transferred to an organic mixture, Agrosoil™. Subsequent growth rates in Agrosoil™ were higher than in other potting media tested. On the other hand, the response of each clone was highly variable, some exhibiting 75% root formation at 60 days while others displayed little response.

ISSN:0114-0671    

DOI:10.1080/01140671.1998.9514040

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Bacillus thuringiensisisolated from a range of geographic sites and from various substrates in New Zealand were serotyped to determine whether or not novel serovars were present in this country. Eighty‐four isolates ofB. thuringiensiswere classified according to their serovar status. Seventy‐nine isolates were classified into 15 known serovars. Five isolates could not be typed. No new serovars were discovered.

ISSN:0114-0671    

DOI:10.1080/01140671.1998.9514041

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor