A mutation affecting curd colour in cauliflower (Brassica oleracea L. var. Botrytis DC)

Summary A single gene mutation in cauliflower resulted in the production of an orange coloured curd when heterozygous, and a stunted orange curd when homozygous. The orange heterozygote has commercial potential.     

花椰菜生长异常的原因及预防

花椰菜营养丰富、品质细嫩、清香可口,是城乡居民喜欢的常食蔬菜之一.但在生产中经常发生生长异常现象,严重影响了质量和产量,使许多种植者蒙受经济损失.根据多年的调查研究结果,对常见的几种生长异常现象进行分析,并提出预防措施,为广大种植者提供参考.     

Conformation of cauliflower curds

Cauliflower curds are composed of numerous small identical whorls. In the autumn cauliflower variety Meroni Ugo these form small pyramidal replicas of the whole curd while they are less pronounced in early summer and most other autumn cauliflower varieties. By halving the curd and its primary and secondary whorls it was possible to draw and measure the angle formed by the sides. There was good correlation between the angles of the primary and secondary whorls but less between these and the whole curd.Measurements were made of curd angles of parents and F₂ progenies from the cross Meroni Ugo × No. 35, the extremes for pyramidal and smooth curds respectively. The F₂ progenies showed a range of angles between those of the parent varieties with a slight excess of curds in the smoother or shallower angle type. It was considered that factors affecting curd conformation were polygenically inherited and that there was slight dominance of the polygenes giving smooth curds.     

Evolution of cauliflower types grown in Great Britain as indicated by the isoenzyme composition of the cauliflower curds

Summary The curds of cauliflowers (Brassica oleracea var. botrytis L.) which are representative of the European biennials, European annuals and Australian types were used to extract 12 of the enzymes involved in carbohydrate and amino acid metabolism. Each enzyme was separated into their isoenzymes using polyacrylamide gel electrophoresis. Two enzymes, acid phosphatase EC 3.1.3.2. and aspartate aminotransferase EC 2.6.1.1. were shown to have different numbers of isoenzymes depending upon which of the three main groups of cauliflower cultivars were used. The enzymes examined showed evolutionary divergence of the cauliflower types during the selection for different times of development.     

The use of aseptic meristem culture in cauliflower breeding

Summary The upper surface of the cauliflower curd consists of a mass of apical meristems. These would normally develop into flowers, but if devernalised they revert to the vegetative phase and develop into leafy shoots. This property is being exploited by aseptically culturing portions of the curd in order to generate clones of selected material.     

Investigations into the breeding system of cauliflower

In experiments to study the effect of inbreeding, I₁ progenies of summer cauliflower showed a trend towards increase in plant weight over their non-inbred commercial parents. Curd quality, however, showed no significant improvement.As summer cauliflower varieties tended to behave as pure lines, studies were made on F₁'s from crosses between five commercial varieties. The main results of hybridisation were an increase in earliness, and a slight, though significant increase in curd size over the parental varieties. It is suggested that summer cauliflowers have attained a state of homozygous balance, which could be emulated in the autumm and winter types, by selection of self-compatible individuals.     

Further studies on the propagation of cauliflower

Use of carefully lifted, decapitated cauliflower plants with 6 to 7 leaves per se, eliminated the need of the rooting of shoots and provided seeds in reduced time. Previously, shoots obtained from decapitated and de-leafed plants were rooted and allowed to produce seeds. This latter method did not assure that seed would be available in time for the following season's planting.     

Selection against the bracting defect of cauliflower

Summary The appearance of bracts through the surface of the cauliflower curd had a heritability estimate of 0.73 ± 0.10 based on the regression of progeny on parent when grown under field conditions. When curds were taken from field grown plants and aseptically cultured, their bracting characteristics were enhanced. It is advocated that a two-tier system of selection, firstly in the field and then in culture, would increase the likelihood of breeding bract free cauliflowers.Also, Department of Biological Sciences, The Polytechnic, Hatfield, Hertfordshire, UK.     

Vegetative propagation of autumn cauliflower

The breeding of autumn cauliflowers is difficult because the selected plants usually die in the field, or after transplanting under glass. A technique of vegetative propagation has been devised whereby selected curds are divided into portions which are then grafted on to root stocks of winter cauliflower raised in pots in the glass-house.Flowering shoots were produced four to eight weeks after grafting and up to two grams of seed was obtained from each curd portion. Seed for further breeding was obtained from 73% of the plants originally selected.     

Propagation and flowering of cauliflower

Summary Production of seed from selected plants in the shortest possible time is an important factor in the improvement of cauliflower. A requirement of the propagation technique is that it should not diminish plant growth. A modification in technique, previously reported, which included a portion of the curd in decapitation of the selected plants made it possible to obtain flowering in approximately 65 days after moving the plants to the greenhouse.     

The inheritance of curding periods in early summer and autumn cauliflower

Two series of diallel crosses were made between (a) eight varieties of autumn cauliflowers and (b) six inbred lines from a single variety of early summer cauliflowers in order to study the inheritance of curding periods. F₁'s and parents from each diallel were grown in separate randomised block experiments and the analyses presented as conventional Wr Vr graphs.The array points from the diallel analysis of autumn cauliflowers were spread along a regression line of unit slope thus indicating that the gene system controlling curding periods was additive with no evidence of gene interaction in these crosses. Varieties of early/mid period maturity with the exception of Veitch's Autumn Giant possessed most dominant polygenes while late maturity was controlled by recessive polygenes. The diallel analysis of curding periods for the early summer cauliflower inbreds indicated the presence of some interaction which was due to the influence of two lines. On reanalysis without these lines the regression of Wr Vr agreed with a slope of 1, although there was a higher degree of dominance than was shown by the autumn cauliflowers. Analysis of the early summer cauliflower lines for numbers of leaves produced before curding indicated an association between low leaf numbers and early curding, and between high leaf numbers and late curding.None of the F₁ hybrids in either series of crosses curded earlier than the earlier curding parent.     

Vegetative maintenance and propagation of cauliflower

1. 1.
   During the past 7 years research has been carried out on different propagation methods for cauliflower. Propagation from root-shoot cuttings proved to be the most efficient method. It was developed at the Institute of Horticultural Plant Breeding, Wageningen. The results obtained with it are generally satisfactory.     
   
   

Improved selection against the purple colour defect of cauliflower curds

Summary Purple colourations of the cauliflower curd detract from the commercial value of the crop. Curds were found to develop purple colourations when in aseptic nutrient culture, and this was correlated with their inherent tendencies to form purple curds in the field as revealed by a progeny test. It was advocated that selection against the defect in the field should be supported by assessment in culture.     

西宁地区花椰菜采种技术

花椰菜由甘蓝演化而来，１９世纪中叶从欧洲和美国引进我国。西宁市地处青藏高原东部，位于东经１００°５２＇～１０１°５５＇，北纬３６°３１＇～３７°２８＇，属大陆高原半干旱气候。河川谷地海拔２１７０～２３５０m，全年日照时数为２５６０～２８３０小时，年总辐射量     

Curd grafting as an aid to cauliflower breeding

Euphytica - Genetic improvements of autumn cauliflower have been impeded by difficulties in seedling plants selected from the field. A technique for grafting cauliflower curd portions on to young...     

Methods to determine solidity and dry matter content of onions (Allium cepa L.)

Summary Different testing methods to measure solidity and dry matter content of onion bulbs were examined. The correlation coefficients between the characters determined were calculated. No strong correlations were found between the results of the different methods of measuring solidity. The refraction value of the press juice gives reliable information on the dry matter content of the onion bulb.     

Portable powder duster — An aid in cauliflower propagation

Summary Propagating summer cauliflower selections for seed production has been difficult due to soft rot and other diseases. A portable compressed air powder blower and evaporative cooling in the greenhouse has increased the percent surival of selected plants for seed production.Michigan Agricultural Experiment Station Journal Articule No. 7105.     

Investigations on the inheritance and responses to selection of riceyness in early summer cauliflower

F₁'s grown from crosses between cauliflower plants with perfect and very ricey curds showed a continuous distribution in the degree of riceyness (classified into four grades) with slight dominance of the most ricey grades. The effect of environment upon the expression of riceyness was shown, by X² tests on F₁'s, F₂'s and selfed parents grown in more than one year, to be limited.Selections made consistently over three generations for grade 1 curds resulted in marked increases in the proportion of curds in that grade, but selection for grade 2 and 3 curds over two generations was less successful. When disruptive selection was practised, i.e., the selection of plants showing a different grade from that for which the parent was selected, the progenies of these plants generally showed an increase in the proportion of the newly selected grade.From these results it was concluded that the inheritance of riceyness appeared to be under polygenic control and that plants were still heterozygous for polygenes at the F₃ generation.     

Investigations into the breeding system of cauliflower Brassica oleracea var. botrytis (L.)

Incompatibility reactions of 21 varieties of summer, autumn and winter type cauli-flowers were assessed by

1. (a)
   comparing the seed sets per siliqua from separate inflorescences of the same plant which were self-pollinated and mixed-pollinated with self and Brussels sprout pollen,