Immature Flowers Research Articles

A comparative study of genotypic and environmental response to androgenesis in Nicotiana rustica

A total of six genotypes of Nicotiana rustica comprising the two F1's (V2 × V12 and V1 × V5) and their parents were evaluated for their efficiency in haploid production. Excised immature flower buds with pollen at late uninucleate to early binucleate stage were pretreated for 21 days at 5 ° or 7 °C, or for 15 days at 9 °C before culturing on Nitsch's medium+ 0.1 mg/l NAA. The effects of genotype, pretreatment and their interaction were tested on anther response, anther productivity and days to first plantlet formation. Highly significant genotype X pretreatment interaction and differences between genotypes were observed for all three characters. Significant differences between pretreatments were observed for anther productivity only. The performance of V12 both in respect of anther productivity and response was highest whereas that of V5 was the lowest. Analysis of variance showed that a simple additive genetic model was not adequate to explain the above variation due to significant additive genetic and dominance interactions with the pretreatment.

ハッサクの自家不和合性に関する研究

Experiments were carried out to increase information about self-incompatibility in Hassaku(Citrus hassaku hort. ex Tanaka). The following results were obtained.1. Using isoelectric focusing analysis, sequential changes of buffer-soluble glycoproteins in self-pollinated pistils were compared with buffer-soluble glycoproteins in the pistils that were cross-pollinated with Hyuganatsu(C. tamurana hort. ex Tanaka). Remarkable differences were observed in the band distribution as soon as 30 minutes after pollination in samples from stigmas, styles, and ovaries.2. Several treatments were tried in search of an effective method of overcoming self-incompatibility. Self-pollination after smearing the Tris-saline buffer extract of the Hassaku or Hyuganatsu pollens onto the stigmas of immature flower buds was found to be the most effective of the treatments. Self-pollination onto the stigmas of mature flower buds 1 hour after cross-pollination with the pollen grains of trifoliate orange (Poncirus trifoliata Raf.) was also effective in producing self-fertilized seeds, though less practical than the former treatment.

Sexangularetin 3-glucoside-7-rhamnoside from gossypium hirsutum

A new diglycosylated flavonol was isolated from immature flower buds of the cotton plant Gossypium hirsutum. The structure was determined to be the 3-glucoside-7-rhamnoside of 3,5,7,4′-tetrahydroxy-8-methoxyflavone.

ヒュウガナツ幼蕾の生理学的特性と自家不和合性について

ヒュウガナツ幼蕾の生理学的特性と自家不和合性について

Plantlet Formation by Anther Culture of Citrus aurantium L.

An anther culture technique was employed in Citrus aurantiuln L.; 'Sour Orange', 'Bouquet', and two varieties grown in Japan, 'Kabusu (Shu-to)' and 'Choshu-to'. Anthers collected from immature flower buds were cultured on the MURASHIGE and SKOOG's (19692) medium supplemented with or without indole-3-acetic acid (IAA) and kinetin at 28°C in darkness. Embryoid formation vvas generally evident 14 weeks after inoculation of anthers of 'Sour Orange' and 'Choshu-to'. Anthers containing pollen grains at the late uninucleate stage formed embryoids effectively on media with 0.02mg/l of kinetin. Nuclear divisions of pollen grains and multinucleate pollen grains were observed in the 'Sour Orange' an-thers, while embryoids from pollen grains were not observed microscopically so far. After the incubation in light with a 16-hour photoperiod, some of these embryoids differentiated into shoots, developing into plantlets, while some of the other embryoids produced more embryoids mainly from the hypocotyl region. Induction of roots and shoots was stimulated by transfer from the embryoid induction media containing growth regulators to a medium eliminated growth regulators. Root tip cells of some of the differentiated plantlets had the diploid chromosome number.

ヒユウガナツの自家不和合性に関する研究 (第2報)

Experiments were carried out to obtain further information about self-incompatibility in Hyuganatsu, Citrus tamurana hort. ex Tanaka. The results obtained were as follows.1. Using disc electrophoresis, sequential changes in buffer soluble proteins and peroxidase isozymes in self-pollinated pistils were compared with those cross-pollinated with Hassaku, Citrus hassaku ex. Tanaka. Remarkable differences in the band distributions of buffer soluble proteins were observed in samples from stigmas, styles and ovaries at any time within 24 hours after pollination. Differences in peroxidase isozyme distributions between self-and cross-pollinations appeared first in the ovaries, second in the styles and last in the stigmas.2. Several treatments were tried in search of an effective method of overcoming self-incompatibility. Self-pollination after smearing the stigma exudate of mature Hassaku flower buds onto the stigmas of immature Hyuganatsu flower buds, half the length of mature ones, was found to be the most effective of the treatments tried. Repeated pollination of immature flower buds for 4 continuous days was nearly as effective as the preceding treatment. With both treatments, a number of small seeds, 1/3 size of normal ones, developed; these might be expected to be seedless triploids.

Cytogenetic studies on the F1 hybrid Solanum indicum x S. torvum

The F1 hybrid Solanum indicum x S. torvum could be maintained only under special conditions. Meiosis was highly irregular: about 45% of chromosomes remained as univalents and wherever pairing was observed, it appeared to be loose. A maximum number of three higher chromosome associations other than bivalents, including 'Y' and 'spoon' type associations, indicate extensive chromosome repatterning. Occasional occurrence of twelve bivalents per PMC suggests that, notwithstanding the extreme divergence, the species have retained sufficient ancestral chromosome homoeologies. Chromosome distribution at anaphase-I was highly irregular and precocious division of chromosomes was observed frequently. This hybrid was 100% sterile and the dropping off of immature flower buds was observed.

ハッサクの自家不和合性に関する研究 (第1報)

In the present experiment, some morphological and histological observations were made by means of both scanning electron and fluorescent microscopy concerning self-incompatibility in Hassaku, Citrus hassaku hort. ex Tanaka. Meanwhile, various treatments were tried in search of an effective method to overcome the self-incompatibility.1. The pollen behavior on stigmas of self-pollinated mature flower buds was compared with that of buds cross-pollinated with Hyuganatsu, Citrus tamurana hort. ex Tanaka. Soon after cross-pollination, the stigma exudate began to co ver the pollen grains; 9 hours after pollination, the pollen grains were completely covered by the exudate. In contrast, self-pollinated pollen grains were not covered by the exudate so quickly as cross-pollinated grains, and individual grains were observed rather clearly on some parts of the stigma even 9 hours after pollination. Furthermore, the germination vigour in the case of self-pollination seemed to be a little weaker than that in the case of cross-pollination.2. The amount of stigma exudate observed on immature flower buds, half the length of mature ones, was clearly less than that on mature flower buds which were to open the next day. Many papilla cells were clearly observed on the stigmas of immattre buds. When immatre flower buds were self-pollinated, and their stigmas were observed 24 hours after pollination, almost all the pollen grains were still cleary visible, because of the lesser secretion of stigma exudate. Germination vigour was also somewhat weaker than in the case of self-pollination on mature flower buds.3. The pollen tube growth was observed after self-and cross-pollination on both mature flower buds and immature ones. In the case of mature flower buds, the pollen tubes of Hyuganatsu penetrated into the ovaries by the 5th day after pollination. However, almost all the pollen tubes of Hassaku were still in the stigma even 9 days after pollination. In the case of immature flower buds, the pollen tubes of Hyuganatsu grew rapidly into the styles; the number of the pollen tubes which had penetrated into ovaries by the 9th day after pollination was five times larger than that observed in the case of cross-pollination onto mature buds. On the other hand, all the pollen tubes of Hassaku had not reached the lower portion of thepeated e styles even 9 days after pollination.4. Repated pollination of immature flower buds for 4 continuous days was found to be most effective for obtaining the self-fertilized seeds among all the treatments used.

Growth and Development of the Shoot, Roots, and Central Bulblet of Tulipa gesneriana L. cv. Paul Richter During Standard Forcing1

Abstract Using a standard forcing program for early February flowering, the histogenesis of the tulip apical meristem from the vegetative state to the differentiated, immature flower was observed with the scanning and light microscopes. Root and central bulblet development were observed only with the light microscope. Total scape and root growth were measured from initiation to anthesis. The apex was vegetative on July 21, prefloral on August 1, and reached the reproductive stage “G” on August 15. The first internode was formed by August 7 and the last internode was formed just prior to reaching stage “G”. Cell division was observed in the scape from formation until after planting at 9°C. A second phase occurred in the epidermal cells, nodal regions, and vascular bundles immediately after the plants were placed in the greenhouse. It preceded the rapid rate of cell elongation in the scape. Root initiation had commenced by late July. Root growth and differentiation continued in the basal plate until mid-September, resumed during the cold treatment, and continued after the plants were placed in the green-house. The central bulblet was initiated by early August and continued to develop throughout the forcing program.

Effects of Day and Night Temperatures and Carbon Dioxide Enrichment on Yield of Glasshouse Tomatoes

SummaryDay temperatures above 64 °F (17.8 °C) and night temperatutes above 60 °F (15.6 °C) increased early yield but not total yield of November-sown tomatoes. Gross monetary returns for the whole crop increased with temperature only when C02 enrichment was given. Higher day temperatures in stage 1 (pricking-out to appearance of immature flower buds) were more beneficial than higher night temperatures, although the opposite was probably true in stage 3 (first anthesis to one month after first fruit harvest). High temperature in stage 2) and low f temperature in stage"(flower bud appearance to first anthesis) enhanced flower and fruit development in the lower trusses, but high temperature in stage 3 reduced the number of fruits in most trusses. C02 enrichment increased the early crop by 90% and the total crop by 30%. Monetary returns for the whole crop increased by 37 %. The gain from enrichment was mainly due to increases in fruit number and size. Enrichment advanced the date of flowering of the first truss, but no furthur advancement was recorded for subsequent trusses.The proportion of fruit marketed as ‘select’ grade tended to increase with temperature, but CO2 enrichment significantly reduced the proportion, probably as a consequence of a shift to larger-sized fruits.

Improved callogenesis and plant regeneration from immature male flowers of East African highland banana cv. “Nakitembe” (AAA-EA)

Application of biotechnological tools in breeding, germplasm conservation and propagation of the East African bananas (Musa sp.) is limited by the crop’s recalcitrance to somatic embryogenesis. This study was undertaken to establish an efficient callus induction and plant regeneration protocol from immature male flowers in the most commercial and farmer preferred banana cultivar “Nakitembe”. Embryogenic callusing was improved from 2.9% on conventional MA1 culture medium to 4.2% with 500 mg L-1 L-Glutamine, 500 mg L-1 L-Proline and 300 mg L-1 casein hydrolysate supplements. A combination of the three amino acids with Chui N6 salts yielded the highest callusing of 10.2%. Cell suspensions were developed and maintained on conventional MS based MA2 medium. Subsequently, the highest efficiency of embryos germination (up to 80%) was achieved on MA4 medium, supplemented with 2.25 mg L-1 BAP and 0.2 mg L-1 IAA. The developed protocol has been successfully applied in Agrobacterium mediated genetic transformations of this variety.

Biosystematics of Two Perennial Species of Helianthus (Compositae), II. Natural Populations and Taxonomy

The purpose of this report is to present the results of observations on natural populations of two perennial, diploid species of Helianthus. This investigation has been supplemented by an analysis of chromosome behavior, comparisons of herbarium collections, experimental hybridizationis, and studies of transplants in the garden (Long 1960). The main objective has been to clarify the taxonomy of the species by bringing to bear facts obtained from diverse lines of work. A synopsis of the species in question has already been published (Long 1954), and the nomenclature of the present paper follows that of the earlier onie. In the introduction to his monograph of Ielianthits, Watson (1929) stated that related species have a most perplexing telndenicy to fade into one another. Extremes are easily recognized but there will always be large numbers of specimens that do not fully satisfy the definitioni of either of two species, and these can be as logically placed with one species as with the other. A plant taxonomist working in Indiana, Ohio, or Wisconsin is able to verify Watson's observation particularly as it applies to H. giganteus L. and H. grosseserratus Martens, the subjects of this report. Large numbers of specimenis of these species do riot fit conveniently into either category. The species are partially sympatric, occurring together in precisely those areas where taxonomic difficulties are encountered. Preliminary field studies showed that the two species can be found in the same habitat, and putative hybrids were identified in population samples from northern Indiana (Long 1955). Herbarium collections from recions of overlap suggested that hybridization was widespread. That natural hybridization could be the cause of the confusing variation was demonstrated by the production of fertile, vigorous artificial F1, F2, and backeross hybrid progeny. In 1956, 1957, and 1958 field investigations were undertaken to determine the extent of hybridization that took place between the two species, with special regard for Ohio populations. To assess properly the degree of interbreeding, population samples from Ohio were compared with those from areas where the species do not commonly occur together. Samples of giganteuts were taken in southern Michigan and of grosseserratus in central Illinois. These latter are assumed to be more or less "pure" collections of each species. Table 1 lists the materials used and their origins. Each population sample included approximately 25 individual specimens obtained by a method previously described (Long 1959). In addition, transplants were takeni for the experimental garden, soil samples made, and flower buds collected for cytoloo'ical observations. Nineteen characteristics were measured in samples, but after close study it was possible to measure species-differences adequately by means of 8 characteristics. A hybrid index based on 6 of these was constructed. The characters and their relative values are given in Table 2. Cytological preparations were obtained by using immature flower buds

Self- and cross-fertility in field beans (Vicia faba Linn.)

1. Controlled self- and cross-pollinations were performed on field bean plants. It was found that while manipulation of the flower stimulated seed setting, both self- and cross-pollination were equally effective.2. Estimations of pollen germination on artificial medium, to which had been added extracts of styles or ovaries from the same or a different plant, gave some slight evidence of a specific inhibition by ‘self’ extracts. No analogous effect was detected on pollen tube growth.3. Experiments in which the style was cut at varying intervals after pollination detected no difference between self- and foreign pollen in rate of growth through the style. Pollen placed on stigmas of immature flowers began growth at once although the fertility achieved was less than when mature flowers were used.4. The composition of seed from mixed self- and cross-pollination was examined. Early application of foreign pollen increased the proportion of crossfertilization but the results were similar in hybrids and inbreds.5. Flower manipulation was more effective in stimulating seed setting than shaking the plants. Spraying with hormone solution was ineffective.6. It was found that plants varied in their capacity to set seed without flower manipulation (autofertility). Hybrid plants were more autofertile than plants from inbred lines.7. X-ray pictures of unopened flowers suggested that the pollen may be more abundant and less diffuse in hybrids than in inbreds.8. The expression of autofertility was affected by many genetic factors.9. Seed produced by open pollination of F1 hybrids contained a much higher proportion derived from self-pollination than did seed from inbred plants grown in the same plot. Possible explanations for this difference, and some consequences for the population genetics of the species, are discussed.