摘要:

This review outlines the potential for developing a reliable transformation system for onions(Allium cepa).A summary of the onion tissue culture literature is presented along with descriptions of the gene transfer systems available. The most suitable regulatory sequences and selective genes that could be used for onion transformation are described, together with the problems which may be encountered following the integration into the particularly large genome of onion. The review proposes likely routes by which transformation and regeneration may be achieved, and suggests possible characteristics of onions which may be altered using such a technique.

ISSN:0114-0671    

DOI:10.1080/01140671.1995.9513895

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Flight activity ofPsila rosaeF. (Psilidae) was monitored with yellow sticky traps (Rebell®) in the North and South Islands of New Zealand over a 13‐month period in 1993/94. Three distinct periods of adult flight activity were observed, indicating three generations per year. At Lincoln (the South Island site), the first flies were caught in early October 1993 and the first flight peaked in mid‐late October, followed by a second peak in mid‐late January, and a third peak in mid March‐mid April. At Feilding (the North Island site), the peak catches of second and third generation flies were 10 and 22 days earlier than at Lincoln, respectively. In both islands, more female than male flies were captured in the first and second generation flight periods whereas more males than females were captured in the third generation.

ISSN:0114-0671    

DOI:10.1080/01140671.1995.9513896

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Twenty‐seven Hawke's Bay, New Zealand apple(Malus domesticaBorkh.) pest and disease control “advisers” including horticultural merchant and New Zealand Apple and Pear Marketing Board (NZAPMB) field representatives, private consultants, and apple plant protection scientists (The Horticulture and Food Research Institute of New Zealand Ltd (HortResearch)) were interviewed over the 1993/94 growing season to determine their role in growers’ pest and disease spray decision‐making. Horticultural merchant representatives considered themselves to be the main spray decision‐maker for 40% of growers. In the opinion of the latter, 50% of growers expected the horticultural merchant representative to know more about the problems in the orchard than they did themselves. Plant protection scientists and (increasingly) NZAPMB representatives play an important role in strategic pest and disease advice to the industry. Growers are very well serviced in the Hawke’ s Bay region which has led to an expectation of “free” advice regarding pest and disease management. Spray recommendations from merchant representatives and consultants are generally risk‐free and prescriptive, with a large safety margin applied for unskilled growers. Introducing more complex spray‐saving techniques, or taking full advantage of those that already exist, will require many growers either to upskill themselves, or employ consultants to manage their orchards. NZAPMB/HortResearch seminars and bulletins along with an on‐line advisory service (e.g., Orchard 2000) could play a useful role in educating growers and providing more complex advice. Basic pest and disease identification and biology, together with a knowledge of pesticides are regarded as being essential to manage pests and diseases successfully. Nutritional problems and resistance development are two areas where more knowledge is required.

ISSN:0114-0671    

DOI:10.1080/01140671.1995.9513897

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Four Australian apple (Malus domesticaBorkh.) cultivars that have orchard resistance to black spot,Venturia inaequalis,were investigated for their usefulness as sources of resistance in apple breeding. Test crosses showed that the cultivars ‘Geeveston Fanny’, ‘Tasman's Pride’, ‘Democrat’, and ‘Redbow’ all carried quantitative resistance genes. Unfortunately, because the resistance was inherited by only a small proportion of their progeny these cultivars are not useful sources of black spot resistance in apple breeding. These cultivars have been superseded by modern, higher quality cultivars.

ISSN:0114-0671    

DOI:10.1080/01140671.1995.9513898

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In a test of 30 red raspberry(Rubus idaeusL.), hybrid berry, and Boysenberry(R. ursinusChamisso and Schlechtendal) selections, bred in New Zealand or imported from overseas in recent years, only two were found to be infected with raspberry bushy dwarf virus (RBDV). However, 18 were found to be susceptible to infection by graft‐inoculation with the virus. Results of graft‐inoculating eight New Zealand sources of RBDV to cultivars known to be susceptible to the resistance breaking strain (RBDV‐RB), but immune to the common strain (RBDV‐S), suggests that the resistance breaking strain is unlikely to be present in New Zealand. Testing for RBDV in a number of commercial Boysenberry plantings in the Nelson district, indicated that the virus was widespread there in this crop. In tests to produce an indicator for the leaf yellowing symptom of RBDV, ‘Marion’ blackberry(R. ursinusderivative) proved unreliable, but consistent vivid yellows on the red raspberry cultivar ‘Autumn Britten’ (formerly ‘3676/6') suggest it to be the best indicator yet found in New Zealand. The leaf yellows found on the cultivars ‘Southland’ and ‘Taranaki’ may be non‐transmissible syndromes. Leaf symptoms were not found on Boysenberry following graft inoculation with RBDV, and the leaf symptoms caused by black raspberry necrosis virus (BRNV) were not accentuated when combined with RBDV. When thorny and thorn‐free Loganberries(R. loganobaccusBailey) were graft‐inoculated with RBDV, no degeneration of growth was observed.

ISSN:0114-0671    

DOI:10.1080/01140671.1995.9513899

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The effect of varying sodium hypochlorite (NaOCl) concentrations and immersion times on sprout suppression in sweetpotato(Ipomoea batatas(L.) Lam.) roots was examined. Treatments included immersion times of 20, 60, and 180 min by solutions containing 0, 0.33, 1.0, 3.0, and 9.0% NaOCl by volume, in all combinations. The aim of the experiment was to find combinations of NaOCl concentrations and immersion times that would minimise sprout production while maintaining root quality. Root quality was defined by the frequency of surface lesions and weight loss during storage. Sprout production was significantly(P< 0.05) reduced, but at the expense of root quality. No combination of factors gave comprehensive sprout inhibition while maintaining root quality at an acceptable level.

ISSN:0114-0671    

DOI:10.1080/01140671.1995.9513900

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The influence of climatic factors on the baking quality of bread wheat was explored by establishing relationships between Mechanical Dough Development (MDD) bake scores and monthly temperature and rainfall from November to January. Wheat quality data forTriticum aestivumL. cultivars ‘Rongotea’, ‘Oroua’, and ‘Otane’ were collated from recommended list trials in Hawke's Bay, Manawatu, Canterbury, south Otago, and Southland, New Zealand, over the seasons 1974/ 75–1991/92. Only weak relationships were established between autumn sown wheat quality and climatic factors. In contrast, there were strong influences of temperature (positive) and rainfall (negative) on the quality of spring sown wheat. The baking quality of ‘Oroua’ and ‘Otane’ were affected by January temperatures and December‐January rainfall. For ‘Rongotea’, November‐December mean temperature and December rainfall were the most important climate factors. The models indicated that central Marlborough and north Canterbury have the best climates for high quality bread wheat. However, analysis of the Lincoln climate record from 1864 to 1994 showed that climate factors alone could cause ‘Otane’ MDD bake scores to vary over a range of 19–29. The analysis highlighted that useful relationships exist between climate and wheat quality, which can be used to assess the impacts of both spatial and temporal climate variability and change.

ISSN:0114-0671    

DOI:10.1080/01140671.1995.9513901

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Onion(Allium cepaL.) cultivars were evaluated to identify those that were sufficiently adapted to produce profitable crops for export in Canterbury, New Zealand. Cultivars were chosen from latitudes similar to Canterbury within four main geographic regions: North America, northern Europe, Japan, and Australia/New Zealand. Cultivars were grown for three seasons and evaluated for maturity, yield, bulb size, bulb shape, skin colour and number, single centredness, and propensity to bolt. The characteristics were assessed relative to the industry standard, ‘Pukekohe Longkeeper’. No one cultivar was better than ‘Pukekohe Longkeeper’ in every characteristic. North American cultivars had good size, shape, skin colour, skin retention, and single centredness, but they were later maturing than ‘Pukekohe Longkeeper’ and had a high propensity to bolt. Northern European cultivars had a similar tendency to late maturity and high bolting percentage. A group of Japanese cultivars were earlier maturing than ‘Pukekohe Longkeeper’ (up to 30 days) and had a low bolting percentage, but they were lower yielding. Another group of Japanese cultivars were higher yielding but they were later maturing with a bolting incidence of 35–50% and were variable in their single centredness and skin colour. Australian cultivars were very similar to ‘Pukekohe Longkeeper’, with negligible bolting. One New Zealand cultivar had a similar yield and 7 days earlier maturity. Only one cultivar, ‘Eskimo’, of Japanese origin was superior to ‘Pukekohe Longkeeper’ in environmental adaptation and quality. ‘Eskimo’ was higher yielding, early maturing, and superior in colour, skin retention, and single centredness. Bulb shape and bolting incidence were acceptable.

ISSN:0114-0671    

DOI:10.1080/01140671.1995.9513902

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A seedling population ofBoronia megastigma(Nees) plants was established to explore the extent and degree of variation in plant and chemical characteristics and to select plants of superior performance in the production of aromatic concretes for commercial use. Obvious variations between selected individual plants were found in plant habit, growth vigour, flower yield, ease of flower removal for harvesting, concrete yield, β‐Ionone and monoterpene content, and the proportion of “volatile” components in the concrete. Selection of elite plants on the basis of so many different criteria is difficult. Quality indices were calculated by incorporating the criteria for each plant into a single value that could be used to rank the plants on plant, chemical, or combined criteria. Ranking using plant and chemical indices gave very different results. Ranking using a quality index that incorporates all criteria offers the opportunity to apply differing weights to individual characteristics. Examples of weighting different criteria are given and the use of weighting is discussed.

ISSN:0114-0671    

DOI:10.1080/01140671.1995.9513903

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Eighteen‐year‐old, top‐dominant central leader trees of ‘Granny Smith’ apple(Malus domesticaBorkh.) were restructured during the 1987 and 1988 dormant seasons into either palmette central leader (initially) or pyramid central leader forms. In the palmette form, pruning was restricted to the total removal of the uppermost east‐ and west‐facing fruiting scaffolds in 1987, and the shortening of all middle scaffolds and the upper north‐facing scaffold in 1988. In the pyramid form, major scaffold limbs were subjectively removed or shortened to reestablish the desired pyramid shape over the two dormant seasons. Both forms were also renewal pruned annually to totally remove pendant fruiting laterals and spur‐bearing wood over 4 years old. In addition, unmodified top‐dominant trees that were either renewal pruned or containment pruned (primarily heading cuts) were maintained for comparison with the restructuring treatments. The restructuring treatments resulted in improved light penetration to the lower and inner canopy regions, improved spur quality, and in a greater proportion (50% cf. 30%) of the fruit being borne in the lower half of the tree. Cumulative yield over the 3 years of study was not reduced in the restructured trees in comparison with the containment‐pruned top‐dominant trees and was reduced by only 20% in comparison with the renewal‐pruned top‐dominant trees. Mean fruit size in both the upper and lower tree regions was not altered by the restructuring treatments. Renewal pruning alone compared with containment pruning resulted in a total yield gain of 28% and an 8% increase of mean fruit size in the lower canopy but did not lead to a redistribution of fruit within the tree. Major upper canopy restructuring combined with annual renewal pruning, therefore, achieved the greatest gains in both yield, and fruit size along with improved fruit distribution within the tree.

ISSN:0114-0671    

DOI:10.1080/01140671.1995.9513904

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor