Root Color Research Articles

Inheritance of Root Color and Carotenoid Synthesis in Carrot, Daucus carota, L.: Orange vs. Red1

Abstract The genetic control of root color and carotenoid synthesis in carrot, Daucus carota L., was studied using 3 carrot cultivars, Kintoki Heian Nagabuto, KHN: Kintoki Osaka, KOS: Kintoki Davis, KDA, and 1 inbred line (W93). Genetic models describing the inheritance of red roots in the F2 were tested in backcross and F3 progenies. In Kintoki cultivars the major pigment is lycopene; beta-carotene is present in smaller amounts; zeta-carotene, gamma-carotene and phytofluene were also detected. In W93 the main pigments are beta-carotene and alpha-carotene; zeta-carotene, gamma-carotene and phytofluene also are detected. The pigments were separated into carotene and carotenol fractions by partition column chromatography. The pigments in the carotene fraction were studied qualitatively and quantitatively by thin layer chromatography. Orange (W93) was dominant to red (KHN, KOS, KDA) in the F1 progeny. The F2 segregation indicated that at least 2 genes are responsible for the differences between orange and red. The segregation of F3, backcrosses, and other progenies revealed the existence of dominant red as well as dominant orange, supporting the digenic composition of F2 populations and indicating the locus with the dominant orange allele to be epistatic to the locus with the dominant red allele. The homozygous recessive would be orange also. The analysis of progenies from the crosses W93 × ‘Kintoki’ suggested a dominant gene for accumulation of alpha-carotene in W93 and a dominant gene for the accumulation of lycopene in ‘Kintoki’.

The shape of leguminous nodules and the colour of leguminous roots

The nodule shape of more than four hundred species of wild legumes indigenous to Rhodesia is found to be related to the tribal classification of the host. Characteristic nodule-shapes of the papilionaceous tribes Galegeae, Genisteae, Hedysareae, and Phaseoleae, and of the subfamilies Mimosoideae and Caesalpinioideae are described and figured. Non-nodulating species were found to have coloured roots much more frequently than nodulating species.

A change in color of aging mycorrhizal roots of Tilia americana formed by Cenococcum graniforme

It is accepted that mycorrhizae formed by Cenococcum graniforme (Sow) Ferd. & Winge are characteristically black. From the data reported here it is apparent that, contrary to this view, mycorrhizal roots formed by this symbiotic fungus may also be brown as well as white. Anatomical studies have led to the conclusion that the differences in color of mycorrhizal roots formed by C. graniforme are related to the physiological state of the symbiotic relationship. Apparently, the white mycorrhizae reflect the early period of the symbiosis and the black mycorrhizae indicate the period at which the symbiotic association begins to deteriorate. Experimental evidence indicates that mycelium of C. graniforme in pure culture changes color through aging and also through certain changes in nutritional conditions.

Inheritance of seed-coat color in the turnlp

It is known that a red-root cultivar in the turnip produces orange seeds, while purple and white root cultivars produce brown seeds. This study was carried out to elucidate the combination of the gene concerning the color of the turnip seed-coat. From the results of experiments, it is considered that the seed color of the turnip is due to the pleiotropism of the conditianal gene P-p determining the root color together with a basic gene C-c. Therefore the brown seed plants have the P gene and the plants of orange seed, the pp gene.

Red‐root in Alfalfa: Inheritance and Relationship with Flower Color1

Inheritance of a character conditioning anthocyanin pigmentation in the roots of alfalfa was determined to be governed by a single dominant gene, Rd, inherited in a tetrasomic manner. The c gene controlling white‐flowers was epistatic to the Rd gene, red‐root being expressed only in plants with colored flowers. The c locus appeared to be a basic color factor for anthocyanin production in all plant parts. The reason for a negative correlation of intensity of flower and root color observed in one family was not evident. Although most of the data were consistent with the hypothesis proposed, the digenic segregations for the Rd and c genes did not fit expected ratios. Linkage and viability problems were among the likely reasons.

Studies on the blindness in gladiolus. VI

A study was made to clarify the problem “nutri-tion and blindness” in gladiolus. According to the design showh in Table 1. three corms each of Spot-light variety (average weight 25. 7g) were planted in sand in Wagners pots on May 26, 1958 and nutritional treatments were made from June 17 to September 13 at 3 day intervals during the course of experiments. Samplings for the chemical analysis were made at the time of flowering, August 21, and at the time of digging, November 5, 1958. Date of flowering, height of plants, number of leaves, and number of florets were recorded at flowering time. Fresh wegihts of tops, of new corms, and of cormels, and number of cormels were measured at digging time. The results obtained are summarized as follows: 1. No significant differences were observed in percentage of flowering, height of plants, number of leaves, and number of florets, even though there were a few blind stalks in -N and several other plots. 2. Earlier flowering was observed in the plots treated with N 200_??_100 ppm and P 50 ppm, and later flowering in -N plots. 3. The color of leaves in the plots supplied with N 50 ppm or -N was yellowish-green, which clearly showed the N deficient symptom, and these plants. showed weaker growth than the others. In the plots: of N 200ppm, the color of leaves showed dark greenb and the plants looked vigorous, but the color of roots: was dark brown and the development of root system, was poor. 4. Fresh weight of tops and of new corms were increased with an increase of nitrogen. 5. Number of cormels was increased in the plots-supplied with low level nitrogen, and decreased remarkably in N 200ppm plots. There was no significant difference in the fresh weight of cormels. 6. Absorption of nitrogen increased with increas-ing of nitrogen supply regardless of application ra-tes of phosphorus or potassium. With increasing of phosphorus increased not only P absorption but also N absorption, except the plot supplied with phos-phorus alone. With increasing potassium increasedi K absorption-slightly when it was supplied with P 25_??_50 ppm or N 100 ppm, and decreased when it was supplied with N 200 ppm. 7. From the results mentioned above, it seemss that nitrogen has a strong relation to flowering in gladiolus, and the optimum of nitrogen application in flowering is 100 ppm. And phosphorus promotes. the effect of nitrogen.

Notes on chimeras in sweet potatoes.

Further studies on the chimeras appearing in the storage roots, stems and leaves of sweet potatoes were made, and some new data are given in the present paper. Agronomic variety OKINAWA-No.l00. In the ordinary strain of OKINAWA-No.l00, the surface colour of storage roots is light red. From this strain, one storage root that was light yellow on its entire surface appeared by somatic mutation. The storage roots of the next generation propagated by stem cutting from this mutant were not always light yellow, and there appeared often the individuals having storage roots that were light red, light yellow or striped or flecked with both colours, though it seems to be accepted usually that mutant colour may be kept in the next generation thus propagated. In view of the fact observed the following passibilities may be cited regarding the causes of this phenomenon. (1) In the light yellow or light red storage roots, the genes in regard to the colour were unstable in the cells of meristems forming the periblem of atems, so that the next generation of such storage roots is not fixed to their colour. (2) Even if the surface of storage roots is light yellow or red, the genes in the cells of meristems forming the periblem of stems may be different from those of the surface of storage roots, the cells of different kind being distributed as Chimeras in the tissues. So that the stems derived from a single storage root of an uniform colour may form storage roots of different surface colour, according to the genes in the tissues from which the stems were originated. Agronomic variety Gokoku. In a large cultivation of GOKOKU, a chlorophyll deficient mutant was found. This plant had four nodes, and the shoot from the undermost one was provided with normal leaves and stems, while those from the other three had chimeral leaves and stems in white and green or in red and green. Observing this chimeral plant morphologically and historogically, the sectorial, the periclinal and the mericlinal conditions in chimeral consitution were found. In the cultivation of OKlNAWA-No.1OO and GOKOKU and other strains of sweet potatoes, various mutants in the colour and other characters occur quite frequently, so that it is quite necessary to pay precise attention in selecting seed storage roots in order to avoid the deterioration of the strains.

ダイコンの色の遺傳研究 (II)

With respect to root color, the following genes may be assumed:G: a gene for pale green neck.C: a gene for flavones as chromogenic substance for the production of anthocyanins.R: a gene for the production of red pigment.B: a gene which produces no color alone, but acts in conjunction with R gene to produce purple pigment.Rs: a gene for red striping.Rf: a gene causing a red coloration of the vascular bundle in all parts of the plant. In the root this gene manifests red flesh. Rf gene is mutable, reverting to its recessive white(Rf→r).Red flesh, red striping, red, and white are so related geneticallythat any two of them taken together give results conforming to amonogenic scheme. Consequently it seems probable that the gene forred flesh constitutes a set of multiple allelomorphs with three genesfor red striping, red, and white.The probable genotype of the root color may be represented as follows:ccrrBBgg, CCrrBBgg……white (white neck), CCrrBBGG……white (pale green neck), CCRRbbgg……red (white neck), CCRRbbGG……red (pale green neck), CCRsRsBBGG……reddish purple striping (pale green neck), CCRfRfbbGG……red flesh (green neck).