Flower Bud Appearance Research Articles

A method for evaluating bolting-resistance in Brassica species

Kale ( Brassica oleracea var. acephala), Chinese cabbage ( B. campestris ssp. pekinensis), chikale ( B. campestris ssp. pekinensis × B. oleracea var. acephala hybrid) and turnip ( B. campestris spp. rapifera) were studied. The proper plant size (number of true leaves) for the beginning of vernalization treatment was determined. All vernalization experiments commenced when the plants were 4 weeks old, with 5–7 true leaves. Plants were classified as bolters either through the visible appearance of flower buds at the apex, or by making longitudinal cuts through the apex if the flower buds were not visible. Cut plants with a pointed apex were classified as bolters. A definite relationship between the number of true leaves and bolting was observed for kale, the more difficult biennial species.

Influence of Air and Soil Temperatures on the Growth and Development of Lilium longiflorum Thunb. during Different Growth Phases

Abstract Yearling ‘Nellie White’ Easter lily plants were subjected to various air and soil temperature combinations to determine temperature requirements for 6 growth phases, each of one-month duration. An air and soil temperature of 24°C favored rapid leaf unfolding, stem elongation, and flower expansion with concomitant depletion of primary scales. After flower buds were visible, soil temperature had no appreciable effect on their rate of expansion; air temperature was the controlling factor. Leaf unfolding rate, stem length, and flower bud size were of equal value in monitoring crop development. Secondary scale initiation and development during the prebloom period was positively related to soil temperature rather than air temperature and was maximum at 24°. The rate of scale initiation progressively decreased from first appearance of the secondary meristem until anthesis of the primary axis. High soil temperature decreased the diameter of the secondary (daughter) axis apical meristem at any time prior to appearance of flower buds on primary axis (buds visible).

Effects of Plant Age on Photoperiodic Induction and Development of Flowers and Fruits in Abelmoschus esculentus (L.) Moench.

Photoperiodic induction and development of flower buds and fruits depend on the age at which short-day (SD) tratment is started. The minimum number of SD, which is required, decreases from 6 to 4 with increasing age up to 10 days. The time from the start of SD treatment to appearance of the first flower buds is constant in all conditions tested except if induction is performed by only 4 SD; in this case, the appearance time is delayed by 6 days. The number of flower buds increased with the number of SD cycles up to 15, and with the age up to 10 days. Likewise, the efficiency of the photoperiodic induction on flower and fruit development increased with the number of SD cycles and with the age of the plant.

Effects of Flower Bud Removal and Nitrogen Supply on Growth and Development of Cotton (Gossypium hirsutum L.)

Effects of flower bud removal for various durations (20 or 90 days following first flower bud appearance or 35 days following first flower opening) and nitrogen supply (non-limiting and 33 % of the nitrogen uptake of non-limited plants) on growth characteristics of glasshouse-grown cotton plants are reported. Removal of flower buds and high nitrogen supply stimulated elongation of the main stem and the number of fruiting positions per plant. Nitrogen supply increased both main stem node number and mean internode length whereas flower bud removal increased only the number of nodes on the main stem. Flower bud removal did not reduce total dry matter yields, number of flowers produced or number of bolls. Vegetative organs provided efficient storage for excess assimilates resulting from the complete suppression of fruiting activity. Plants subjected to nitrogen stress had lower dry matter yield, number of flowers and number of bolls. Compensation following flower bud removal was greater at higher than at lower nitrogen supply. Relative fruitfulness, the partition of biomass between vegetative and reproductive organs, was not affected by either flower bud removal or nitrogen supply.

The effect of level of nitrogen nutrition on earliness in upland cotton (Gossypium hirsutum L.)

The responses of both morphological and product quantity measures of earliness in two cotton cultivars to nitrogen stress applied either continuously or over specific developmental stages are reported. Continuous nitrogen stress increased the number of days to appearance of the first flower bud and first flower in both cultivars, had little or no effect on the main-stem node at which the first-fruiting branch appeared, and increased flower bud shedding only in the less determinate early cultivar Rex. The total number of fruiting points produced up to first flower appearance was reduced by nitrogen stress in both cultivars. Nitrogen stress from planting to appearance of the first flower bud greatly increased the time taken for flowering to occur at the first 30 fruiting points through delaying first flower appearance in both cultivars and increasing the horizontal flowering interval in Rex. Nitrogen stress applied later generally had little effect on this earliness index. Nitrogen stress from planting to first flower bud appearance strongly reduced the production rate index in Rex. However, nitrogen stress from first flower bud to first flower appearance resulted in a rapid rate of seed cotton production in both cultivars. Stimulation over the control was particularly marked in cultivar Bar 7/8. The relationship between earliness index and production rate index was explored, and the nitrogen effects on these indices evaluated. The combined use of these indices in field trials to identify factors limiting earliness is advocated.

Studies on the Effect of Nitrogen and Phosphorus on Chrysanthemum CV. Yellow (Chrysanthemum indicum, L.)*. I. Flowering and Yield

Investigations were undertaken to study the effect of N and P on the flowering of chrysanthemum CV. Yellow. Earliness in respect of flower bud appearance, lower opening and the time taken for flowering were observed with the plants under increased N and P levels. The highest levels of nitrogen (100 Kg/ha) increased the yield of flowers. The weight of hundred flowers was significantly increased by 100 Kg/ha in each of N and P. The size (diameter) of the flower and stalk length were significantly increased in plants receiving the highest levels of N and P. The keeping quality of the flowers was not affected by N and P levels for the first 24 hours but spoilage was concomitant with increase in N level and increased with march of time.

JUVENILITY IN HYBRID TEA ROSES

In Hybrid Tea-roses relations between growth and juvenile period (J.P. = number of days from seed germination to flower bud appearance) were studied for three years. Plants showing a flower bud for the first time are significantly longer than those without a bud. In comparison with plants with long J.P.'s, plants with short J.P.'s have shorter shoots both at bud appearance and at first flowering, flower sooner, are significantly longer when measured on one date, and yield about three times more cut flowers in 6 months. It was shown that the J.P. depends on plant development and does not govern this process.

Juvenility in Hybrid Tea-roses

In Hybrid Tea-roses relations between growth and juvenile period (J.P. = number of days from seed germination to flower bud appearance) were studied for three years. Plants showing a flower bud for the first time are significantly longer than those without a bud. In comparison with plants with long J.P.'s, plants with short J.P.'s have shorter shoots both at bud appearance and at first flowering, flower sooner, are significantly longer when measured on one date, and yield about three times more cut flowers in 6 months. It was shown that the J.P. depends on plant development and does not govern this process.

Annual Flowering and Growth Habit in Cabbage—Broccoli Crosses1

Abstract When inbred lines of cabbage [Brassica oleracea L. (Capitata group)] and green sprouting broccoli [B. oleracea L. (Italica group)] were crossed, F1 plants were annual in flowering, tall, and generally resembled broccoli. Of 2,724 F2 plants, 43% developed visible flower buds during the field-growing season, which appeared to be too short for full expression of annual habit. Annual versus biennial habit and time of flower bud appearance in annual plants seemed to be under quantitative genetic control. Height varied from that of typical cabbage to that of broccoli and greater, and was not related to apparent annual habit or general appearance of the plants. Though some plants resembled cabbage in leaf type and form of the terminal rosette, no typical heading cabbages were recovered.

γ線を照射したチューリップの形態学的研究(第1報)

The present investigation was carried out in order to find out the effects of irradiation on the flower organ formation in tulip and to elucidate the mechanisms of the morphological changes anatomically.The bulbs and plants of tulips at the various growing stages, from the early stage of the flower bud differentiation (July) to the late stage of appearance of flower bud (March) were irradiated with cobalt-60 gamma rays (Table 1, Fig. 1, 3). Dosages employed were 0.5, 1 and 3 krad at dose rates of 1.6×102 and 1.4×104 rad/hr (Table 2).The results of the observation are as follows:

The influence of the photoperiodic regime and red-far red light treatments of Portulaca oleracea L. plants on the germinability of their seeds

Plants of Portulaca oleracea L. were grown in a temperature controlled greenhouse. In one experiment plants received 8 hrs of daylight and during the following 16 hrs ("dark period") they either were grown in darkness or received white, red and far red light of low intensity for various times preceeding the dark period or in the middle or the end of the dark period. In other experiments the plants were grown in photoperiods of 8, 11, 13, 15, 16 hrs and in continuous light. The effect of these treatments on number of leaves until the appearance of the first flower bud and the germination of the seeds collected from these plants were studied. P. oleracea was found to be a photoperiodic facultative or quantitative short day plant. The photoperiodic treatments of the mother plants affect the germinability of their seeds, dependent on the last 8 days of seed maturation on the mother plants. The shorter the daylength the faster the germination. Red or far-red treatments of the mother plant also affect the germinability. But in no case is there dark germination even after 8 days of seed maturation under continuous red light. These results suggest that the influence of the light treatments of the mother plants on the germination of its seeds is not mediated via phytochrome but rather through some other pathway.

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.

Differentiation and growth of a growing point until the stage of flower bud appearance in leading common buckwheat and Tartary buckwheat varieties in northern Japan

Studies regarding the developmental stage of common buckwheat (Fagopyrum esculentum Moench) have not been adequately performed despite its importance in studying the yield-determining process. In addition, the difference between common buckwheat and Tartary buckwheat (F. tataricum (L.) Gaertn.) is still unclear. In the present study, the differentiation and growth of the growing point until the stage of flower bud appearance were evaluated in the common buckwheat variety ‘Kitawasesoba’ and the Tartary buckwheat variety ‘Manten-Kirari’, which are the leading buckwheat varieties in Hokkaido, Japan. With some exceptions, the developmental stages of ‘Kitawasesoba’ and ‘Manten-Kirari’ can be distinguished. Thus, leaf primordia, axillary flower bud, and terminal flower bud differentiations and growths were observed. Both the common and Tartary buckwheat varieties did not exhibit large differences in the morphology of the growing point. However, the two varieties showed differences in the rates of differentiation and growth.Received: April 11, 2019; accepted: June 8, 2019Keywords: common buckwheat, developmental stage, growing point, Hokkaido, Tartary buckwheat

The Flowering Behaviour of Carnation Cuttings Produced in Long and Short Days

Cuttings of the glasshouse carnation, White Sim, were produced in long and short days, rooted and then grown on to produce terminal flower buds. So long as cuttings were made from vegetative shoots, the day- length in which they had been produced had little or no effect on the time of flower-bud appearance. In short days shoots of stock plants remained vegetative for relatively long periods but in long days induction of flowering occurred when the shoots had eight or nine visible leaf pairs. Cuttings made from shoots that had undergone induction flowered rapidly with relatively few leaves below the flower, even under short-day conditions where the flowering of vegetative cuttings was delayed. When cuttings were made from vegetative shoots of the same age, cuttings with higher leaf numbers flowered earlier and after initiating fewer new leaves.

The Emergence and Development of Branches in Crotalaria juncea and their Relationship to Flowering

Nanda, K. K. (Forest Res. Inst., Dehra Dun, India.) The emergence and development of branches in Crotalaria juncea and their relationship to flowering. Amer. Jour. Bot. 49(4): 334–341. Illus. 1962.—Seeds of Crotalaria juncea L. were sown in pots on March 23, 1959, and records were kept of the dates of emergence of individual branches and the appearance of flower buds on them. Periodical observations were also made of the height of the main shoot as well as its branches and the number of nodes and leaves borne by them throughout the year. The main shoot elongates rapidly and terminates in an inflorescence. Development of lateral buds remains completely arrested during the period of rapid elongation and is initiated only after the appearance of the floral buds when it takes place in basipetal sequence. The flowering of the branches also takes place in a basipetal manner. This mode of emergence of branches and their flowering are exhibited even by secondary and tertiary branches. The length attained by these branches is very small as the flower buds appear soon after their emergence. In contrast, the branches formed towards the middle of May continue to elongate for a considerable period and become many times longer than the main shoot or the branches produced earlier in the season. The vegetative period of these branches is also very much prolonged. These differences in the height attained by branches produced at different times of the year and the basipetal sequence in the emergence of branches and their flowering appear to be under the control of some physio-chemical changes which cause the transformation of the growing apex from the vegetative to the reproductive state. This holds good irrespective of whether these changes are brought about as a result of a favorable environmental complex, as is the case with the main shoot and late-formed, much elongated branches, or are due to the favorable internal conditions produced within the plant as a result of the completion of the developmental process of the main shoot, as happens in the case of branches produced earlier in the season.

THE EMERGENCE AND DEVELOPMENT OF BRANCHES IN CROTALARIA JUNCEA AND THEIR RELATIONSHIP TO FLOWERING

Nanda, K. K. (Forest Res. Inst., Dehra Dun, India.) The emergence and development of branches in Crotalaria juncea and their relationship to flowering. Amer. Jour. Bot. 49(4): 334–341. Illus. 1962.—Seeds of Crotalaria juncea L. were sown in pots on March 23, 1959, and records were kept of the dates of emergence of individual branches and the appearance of flower buds on them. Periodical observations were also made of the height of the main shoot as well as its branches and the number of nodes and leaves borne by them throughout the year. The main shoot elongates rapidly and terminates in an inflorescence. Development of lateral buds remains completely arrested during the period of rapid elongation and is initiated only after the appearance of the floral buds when it takes place in basipetal sequence. The flowering of the branches also takes place in a basipetal manner. This mode of emergence of branches and their flowering are exhibited even by secondary and tertiary branches. The length attained by these branches is very small as the flower buds appear soon after their emergence. In contrast, the branches formed towards the middle of May continue to elongate for a considerable period and become many times longer than the main shoot or the branches produced earlier in the season. The vegetative period of these branches is also very much prolonged. These differences in the height attained by branches produced at different times of the year and the basipetal sequence in the emergence of branches and their flowering appear to be under the control of some physio‐chemical changes which cause the transformation of the growing apex from the vegetative to the reproductive state. This holds good irrespective of whether these changes are brought about as a result of a favorable environmental complex, as is the case with the main shoot and late‐formed, much elongated branches, or are due to the favorable internal conditions produced within the plant as a result of the completion of the developmental process of the main shoot, as happens in the case of branches produced earlier in the season.