Inheritance of flower pigments in tulip (Tulipa L.)

Summary In order to investigate the inheritance of flower colour in tulips, seven cultivars were crossed and selfed in a diallel. Of these parents and their F₁'s the relative amounts of carotenoids, delphinidin, cyanidin, pelargonidin, quercetin and kaempferol were determined.For delphinidin, quercetin and daempferol only additive gene action was determined, and for carotenoids, cyanidin and pelargonidin also non-additive gene action and plasmic differences.Biosynthesis of delphinidin and pelargonidin was only found when cyanidin was present, while synthesis of delphinidin and pelargonidin was antagonistic.     

Genetic analysis of cut flower longevity in Gerbera

Summary The vase life duration and stem stiffness of 12 parent clones and 77 progenies of Gerbera jamesonii were studied both in summer and in winter. In winter, vase life was shorter and the stems were weak. Few exceptions from this general pattern were detected. The average vase life duration ranged from 16.0 days for the best to 8.9 days for the worst progeny. Individual plants were selected with a vase life of 20 or more days.The curvature of the stem, measured after 24 hrs dry storage, is associated with the folding of the stem in the vase. Selection for low curvature may decrease the incidence of folding and with it the variation in vase life of Gerbera.     

Inheritance of flower and pod colour in cowpea (Vigna unguiculata L. Walp.)

Inheritance of flower colour and pod colour in cowpea (Vigna unguiculata L. Walp.) has followed a qualitative pattern. Purple flower colour is dominant over white flower colour, whereas black pod colour is partially dominant over white pod colour. A segregation ratio of 3 purple:1 white flowers in F₂ generations of two crosses indicated that white flower colour is controlled by a single recessive. Segregation ratio of F₂ 1 white:2 light black:1 black indicated that black pod colour is partially dominant over white pod colour and is governed by one gene. These results were further confirmed by backcross generations. White flower and pod colour are controlled by single recessive genes on separate chromosome. Gene symbols were assigned. This revised version was published online in July 2006 with corrections to the Cover Date.     

Genetic analysis of flower and lateral shoot production in Gerbera

Summary An incomplete diallel cross with selfs and reciprocals was made with twelve cultivars of Gerbera jamesonii. Very significant differences occurred between GCA's of the parents for cut flower yield, earliness and number of lateral shoots. The selfs were mainly responsible for the significant SCA's.A positive genetic correlation occurs between the number of lateral shoots at anthesis of the first flower and total flower production. The phenotypic performance of parents (measured on cuttings) was poorly related to their breeding value (measured on seedlings). It is suggested that this is due to physiological differences between cuttings and seedlings.     

Inheritance of neurotoxin (ODAP) content, flower and seed coat colour in grass pea (Lathyrus sativus L.)

Summary A strong epidemiological association is known to exist between the consumption of grass pea and lathyrism. A neurotoxin, -N-Oxalyl-L-, -diaminopropanoic acid (ODAP) has been identified as the causative principle. This study was undertaken to investigate the mode of inheritance of the neurotoxin ODAP, flower and seed coat colour in grass pea. Five grass pea lines with low to high ODAP concentration were inter-crossed in all possible combinations to study the inheritance of the neurotoxin. Parents, F₁ and F₂ progenies were evaluated under field condition and ODAP analyzed by an ortho-phthalaldehyde spectrophotometric method. Many of the progenies of low x low ODAP crosses were found to be low in ODAP concentration indicating the low ODAP lines shared some genes in common for seed ODAP content. The F₁ progenies of the low ODAP x high ODAP crosses were intermediate in ODAP concentration and the F₂ progenies segregated covering the entire parental range. This continuous variation, together with very close to normal distribution of the F₂ population both of low x low and low x high ODAP crosses indicated that ODAP content was quantitatively inherited. Reciprocal crosses, in some cases, produced different results indicating a maternal effect on ODAP concentration. Blue and white flower coloured lines of grass pea were inter-crossed to study the inheritance of flower colour. Blue flower colour was dominant over the white. The F₂ progenies segregated in a 13:3 ratio indicating involvement of two genes with inhibiting gene interactions. The gene symbol LB for blue flower colour and LW for white flower colour is proposed.     

The inheritance of flower colour and vegetative characters in Rubus coreanus

Summary Dominant genes An ₁ for pink flower colour and Br ₁ and Br ₂ controlling branching of the canes in Rubus coreanus are described. In an F₁ progeny and in first backcrosses to red raspberry, some seedlings inherited the ability of R. coreanus to form up to three accessory buds per node. Polygenic systems controlling spine number and spine size are described, number and size being positively correlated. It is postulated that the greater size of spines of h (glabrous-caned) plants is due to linkage of a block of size-controlling genes with the H locus. The greater number of spines of H (hairy-caned) plants is attributed to a pleiotropic effect of the H allele. A new type of dwarf, cauli-flower, which occurred in the F₁ and some first backcross progenies, is described.     

Inheritance of white flower colour and congested growth habit in certain Buddleia progenies

Summary Buddleia fallowiana var. alba (FA) was crossed with B. davidii Nanhoensis Alba (NA) and both were crossed with the B. davidii cultivars Pink Delight (PD) and Royal Red; seedlings from the FA x NA progeny were backcrossed to the two parents. The pattern of inheritance of white or coloured flowers indicates two loci controlling white flower colour. FA is homozygous for a recessive gene, labelled alb-1, and NA is heterozygous for a dominant gene, Alb-2.In most segregating progenies some of the white flowered seedlings had a congested habit of growth and this is tentatively ascribed to two dominant complementary genes. NA is heterozygous for Con-1, which is tightly linked with Alb-2. FA and PD are heterozygous for Con-2.     

Inheritance of petal colour and its independent segregation from seed colour in Brassica rapa

The inheritance of petal (flower) colour and seed colour in Brassica rapa was investigated using two creamy‐white flowered, yellow‐seeded yellow sarson (an ecotype from Indian subcontinent) lines, two yellow‐flowered, partially yellow‐seeded Canadian cultivars and one yellow‐flowered, brown‐seeded rapid cycling accession, and their F₁, F₂, F₃ and backcross populations. A joint segregation of these two characters was examined in the F₂ population. Petal colour was found to be under monogenic control, where the yellow petal colour gene is dominant over the creamy‐white petal colour gene. The seed colour was found to be under digenic control and the yellow seed colour (due to a transparent coat) genes of yellow sarson are recessive to the brown/partially yellow seed colour genes of the Canadian B. rapa cvs.‘Candle’ and ‘Tobin’. The genes governing the petal colour and seed colour are inherited independently. A distorted segregation for petal colour was found in the backcross populations of yellow sarson × F₁ crosses, but not in the reciprocal backcrosses, i.e. F₁× yellow sarson. The possible reason is discussed in the light of genetic diversity of the parental genotypes.     

Inheritance of siliqua orientation and seed coat colour in Brassica tournefortii

The inheritance of siliqua orientation and seed coat colour in Brassica tournefortii was investigated using four genotypes varying in these two characters. The F₁, F₂ and backcross generations of two crosses were used for studying the segregation pattern of the traits. The plants were classified for seed colour as having brown or yellow seeds and for siliqua orientation as having upright, semi‐spread or spread siliqua. Seed colour was found to be under monogenic control with brown being dominant over yellow. Siliqua orientation was under digenic polymeric gene action: upright siliqua was produced by the presence of two dominant genes and spread siliqua by two recessive genes. The absence of even a single dominant gene resulted in a third type of siliqua orientation, semi‐spread siliqua.     

Inheritance of siliqua locule number and seed coat colour in Brassica juncea

The inheritance of siliqua locule number and seed coat colour in Brassica juncea was investigated, using three lines each of tetralocular brown seeded and bilocular yellow seeded. Three crosses of tetralocular brown seeded × bilocular yellow seeded lines were attempted and their F₁, F₂ and backcross generations were examined for segregation of these two traits. Brown seed colour and bilocular siliqua characters were found to be dominant over yellow seed and tetralocular siliqua, respectively. Chi‐square tests indicated that each trait is controlled by different sets of duplicate pairs of genes. Bilocular siliquae or brown seeds can result from the presence of either of two dominant alleles, whereas tetralocular siliquae or yellow seeds are produced when alleles at both loci are recessive. A joint segregation analysis of F₂ data indicated that the genes governing siliqua locule number and seed colour were inherited independently.     

Colours of florets of several gerbera (Gerbera jamesonii Bolis ex Adlam) cultivars measured with a colorimeter

Summary The colour variation between several gerbera cultivars were analyzed with a tristimulus colorimeter. A pilot study with a few cultivars showed that the flower colour variation between cultivars and colour effects during the growing season can be calculated quantitatively on the basis of data measured by the colorimeter. On the basis of these results the colour differences between a larger group of gerbera cultivars were measured. A consistent number of cultivars was distinct on the basis of colorimetric data and visual colour assessments.Abbreviations CIE Commission Internationale de l'Eclairage - PBR Plant Breeders' Rights - R.H.S. Royal Horticultural Socicty - UPOV Union for the Protection of New Varieties of Plants     

An HPLC investigation of flower colour and breeding of anthocyanins in species and hybrids of Alstroemeria

The tepals of 28 Chilean species of Alstroemeria and 183 interspecific hybrids were analysed for anthocyanin content by high-performance liquid chromatography (HPLC). The anthocyanins were identified as 3-rutinosides of 6-hydroxydelphinidin, 6-hydroxyeyanidin, cyanidin, and delphinidin and 3-glyeosides of cyanidin and delphinidin, some of which were acylated with malonic acid. Comparisons of the anthocyanin contents in parents and offspring showed that no anthocyanidin or acylation pattern was dominant, and that offspring values were close to mid-parent values for the percentage of malonated anthocyanins, whereas the inheritance of cyanidin, 6-hydroxycyanidin, and delphinidin seems more complicated. Flower colour, hue, and intensity were measured by CIELab in fresh tepals and compared with their anthocyanin content and the estimated flavonoid concentrations. Colour intensity was positively correlated with anthocyanin concentration. Compared with flowers containing exclusively cyanidin 3-glycosides, the hues of flowers with delphinidin 3-glycosides were bluer and with 6-hydroxycyanidin 3-glycosides redder, respectively. Both malonation of anthocyanin and co-pigmentation with flavonoids caused a shift to bluish hues, irrespective of the anthocyanidins. By quantifying both chemical and colorimetric characteristics a model for the effect of anthocyanin on Alstroemeria flower colour was established. Breeding of new cultivars of Alstroemeria is discussed.     

Inheritance of black testa colour in lentil (Lens culinaris Medik.)

The inheritance of testa (seed coat) colour and interaction of cotyledon and testa colours were studied in seven crosses of lentil (Lens culinaris Medik.) involving parents with black, brown, tan or green testa and with orange, yellow or dark green cotyledons. Analysis of F₂ and F₃ seed harvested from F₁ and F₂ plants, respectively, revealed that although black testa is dominant over nonblack testa, its penetrance is not complete since both F₁ plants and heterozygous F₂ plants produced varying proportions of seeds with either black or nonblack testa. The F₂ populations of the crosses between parents with brown and tan, as well as brown and green, testa segregated in the ratio of 3 brown : 1 tan and 3 brown : 1 green, respectively, indicating monogenic dominance of brown testa colour over tan or green. The expression of testa colour was influenced by cotyledon colour when parents with brown or green testa are crossed with those having orange or green cotyledons. Thus F₂ seeds from these crosses with a green testa always had green cotyledons and never orange cotyledons. F₂ seeds from these crosses with a brown testa always had orange cotyledons and never green cotyledons. These results suggest diffusion of a soluble pigment from the cotyledons to the testa. This revised version was published online in July 2006 with corrections to the Cover Date.     

非洲菊切花保鲜中的细菌鉴定和8-HQ抑菌保鲜研究

非洲菊切花瓶插观赏过程中常出现花茎弯曲和花朵下垂现象,该现象与插花溶液中的细菌滋生有关。本研究分离纯化了非洲菊切花清水瓶插中出现的细菌,通过16S rDNA测序法鉴定出瓶插过程中滋生的细菌主要来自泛菌属、假单胞菌属、寡氧单胞菌属以及克雷伯氏菌属;并研究了8-羟基喹啉（8-HQ）抑制泛菌属细菌增长的最低长效抑菌浓度为150 mg/L;选用8-HQ和蔗糖作为切花保鲜剂主要成分时,其中150 mg/L 8-HQ + 6%蔗糖的组合能最有效延长非洲菊鲜切花开放时间,并保持瓶插溶液清亮程度。     

纳米铜加蔗糖处理对非洲菊切花的保鲜作用

为探究新型纳米级无机杀菌剂纳米铜(nano-copper,NC)处理对切花的保鲜效应,以非洲菊(Gerbera jamesonii)'红艳'切花为试材,观测不同浓度NC单独处理及其与蔗糖组合溶液瓶插处理对非洲菊瓶插寿命、观赏品质和水分关系的影响.结果表明,与去离子水处理(对照组)相比,1、3、5mg/LNC单独处理对非...     

Independent Inheritance of Erucic Acid Content and Flower Colour in the C-Genome of Brassica napus L.

The synthetic Brassica napus L. line No7076 was obtained from a cross between yellow-flowered and zero-erucic turnip rape (B. campestris) Sv85-38301 and white-flowered and high-erucic (41.4%) B. oleracea ssp. alboglabra No6510. This synthetic B. napus is pale-flowered and has an average erucic acid content of 25.8 %. It was crossed with the yellow-flowered and zero-erucic B. napus line SvS4-2S053 and segregation of the erucic acid content and flower colour was studied in F₁ and F₂ generations. The high erucic acid content was controlled by a single gene in the C-genome and was additively inherited. Strong evidence was obtained in support of independent segregation of the erucic-arid content and the flower colour characters controlled by the C-genome of B. napus.     

The mechanism of increased seed fertility accompanied with the change of flower colour in Brassicoraphanus

Summary In Brassicoraphanus (amphidiploids between Brassica japonica Sieb. and Raphanus sativus L.), yellow-flowered plants that occurred among originally white-flowered plants showed an increased seed fertility. It is assumed that the gene Y (yellow-flower gene) from Brassica and the gene W (white-flower gene) from Raphanus are located at corresponding loci of only partially homologous chromosomes. W is dominant (epistatic) over Y. The normal white-flowered plants have the genotype YYWW. A YYYW-plant was found, which is assumed to have arisen through crossing-over following multivalent formation. In the progeny of this plant, yellow-flowered plants (YYYY) as well as white-flowered plants (YYWW, YYYW) appeared. The gene for flower colour is closely linked to a gene which controls the development of embryos (or endosperm). This gene promotes the development of embryos in homozygous condition. Therefore, the embryo having only the yellow-flower gene can develop more easily into viable seed than the embryo having the white-flower gene. It is also possible that the sterility of white-flowered plants is caused by a discordance between the cytoplasm of Brassica and W (or genes linked to W) of Raphanus.     

Models of inheritance of flower colour and extra petals in Potentilla fruticosa L.

Summary Inheritance models for flower colour and extra petals in Potentilla fruticosa L. were developed by conducting controlled crosses between different cultivars and advanced selections. Parents were crossed in all combinations and floral character segregation of progenies were recorded. Preliminary models for flower colour include two whitening genes (W₁ and W₂) and two yellowing genes (Y₁ and Y₂) with the action of a bleaching gene also implicated. The cyanic flower colour model developed involves background petal colour, cyanic pigments and distribution and temperature sensitivity genes. The extra petals model involves a two gene switch, D₁ and D₂ to turn on the production of up to five extra petals and a modifier gene, D_m that accounts for an additional one to five extra petals. Either D₁ or D₂ must be recessive to initiate extra petal production. D_m must also be recessive to enable production of an additional 1–5 petals.     

Inheritance of seedling colour in faba bean (Vicia faba L.)

Summary The inheritance of purple seedling colour was studied, in relation to the genetic control of flower colour. It was found that purple seedling colour is likely to be controlled by a single gene and that the trait is dominant over green seedling colour. White flowering prohibited the expression of the purple seedling colour, and is therefore thought to be epistatic.This character can be used to estimate rate of outcrossing in breeding programmes, as well as contribute to our knowledge of the biosynthesis of plant pigments and secondary metabolites such as tannins.     

Genetics of flower colour in China aster (Callistephus chinensis (L.) Nees)

Summary The genetics of flower colours violet, blue, deep pink, pink, light pink, creamy white and white was investigated in 17 cross combinations involving 10 parents in China aster (Callistephus chinensis (L.) Nees). Violet was dominant over all other colours; blue was dominant over creamy white; deep pink was dominant over pink and white, but incompletely dominant over light pink and pink was dominant over light pink and white. Four genes C, R, B and P were found to govern these different flower colours. The gene P had a dominant allele P^D and a recessive allele p.Contribution No. 146/88 of the Indian Institute of Horticultural Research, Bangalore 56080, India.