Tertiary Buds Research Articles

Evaluating the Efficacy of Macropropagation Techniques for Red Banana (Musa acuminata) Using Biocontrol Agents

The corm propagation is an simple, alternative and cheap technique for Banana multiplication. The study on the effect of biocontrol agents on macropropagation of Banana cv.Red Banana was carried out at SRM College of Agricultural Sciences, Chengalpattu. The decapitated and decorticated corms were exposed to various treatments with combination of sawdust and cocopeat media supplemented with different biofertilizers and biocontrol agents comprising 13 treatments in 3 replication adopting Completely Randomized Design and the data recorded underwent analysis of variance (ANOVA). Among the 13 treatments adopted, Cocopeat + Sawdust (1:1) + VAM (30 g/corm) + Pochonia chlamydosporia (60g/corm) showed significantly best result in terms of number of days taken for primary bud emergence (22.7 days), days taken for secondary bud emergence (46.34 days), days taken for tertiary bud emergence (67.35 days), number of primary buds per corm (1.53), number of secondary buds per corm (3.67), number of tertiary buds per corm (4.33), total number of plantlets per corm (9.54), plant height (73.56 cm) and pseudostem girth (12.34 cm). The next better performance was observed in the treatment Saw dust + VAM (30 g/corm) + Pochonia chlamydosporia (60 g/corm) which recorded early emergence of buds and production of more buds. The cormpropagation approach refined in this work is accessible, necessitating less skill and knowledge, making it appropriate for implementation by farmers at the farm level.

Cold Hardiness in ‘Alphonse Lavallee’ (Vitis vinifera L. cv) Grape Dormant Buds and Phloem Tissue: Seasonal Insights and Some Treatment Impacts

Grapes are highly susceptible to cold damage during critical developmental stages, impacting viticulture. Understanding the intricate dynamics of cold hardiness in grape dormant buds and phloem tissue is crucial for developing effective mitigation strategies. In this study, we investigated the LT50 values, representing the temperature at which 50% of buds are damaged, under different treatments and sampling times. In our research, we evaluated the effects of four treatments—potassium oxide (K2O), calcium chloride (CaCl2), seaweed (SW), and a control—on the cold hardiness of grapevine buds and phloem tissue. Primary bud LT50 values varied across seasons, with January at −22.46 °C, February at −22.35 °C, and March at −20.45 °C. K2O treatment showed a trend toward improvement, although the difference from the control (−21.99 °C) was not statistically significant. Regarding LT50 values, CaCl2 and SW applications did not significantly differ from the control. Tertiary buds, however, exhibited a substantial enhancement in cold hardiness with K2O application, displaying significantly lower LT50 values compared to the control (−23.55 °C). Phloem tissue LT50 values did not significantly differ among treatments, showing less variability. Bud water content significantly increased with K2O application in all sampling periods (January: 35.41% vs. 35.61%; February: 34.03% vs. 39.16%; March: 42.40% vs. 37.82%), while shoot water content remained stable. In conclusion, K2O emerges as a key influencer, particularly in enhancing the cold hardiness of tertiary buds. These insights contribute to the knowledge base for targeted frost mitigation strategies in viticulture.

Determination of the Relationship Between the Number of Clusters and Primary Bud Size in Vitis vinifera and Vitis labrusca Grapevines by Histological Sectioning Method

This study was conducted to reveal the relationship between the number of clusters and of primary buds size in dormant grapevine winter buds. In addition, it has been tried to determine how the size of the primary bud and the cluster primordials in it change according to the position on one-year-old shoots. In this study, Vitis vinifera L. cv. ‘Karaerik’ and Vitis labrusca L. cv. 'Ülkemiz' varieties was used. Primary buds are separated from other shoot beds (secondary and tertiary buds) with the a scalpel, and fixation, vacuuming, paraffin impregnation, paraffin embedding, freezing, sectioning and tissue staining were performed, respectively. The stained samples were examined microscopically, images were taken and these images were transferred to the computer and histological analyzes was made. In the study, it was determined that bud sizes including three clusters were statistically different (p < 0.05) from other bud sizes (without clusters, one cluster and two clusters of buds). It was determined that there were statistical differences between cultivars in terms of both bud size and the number of cluster. In addition, it was determined that the middle (0.77) buds of the ‘Karaerik’ variety contained more clusters than the basal (0.66) and apical (0.59) buds, whereas the apical (1.19) buds of ‘Ülkemiz’ variety contained more clusters than the basal (0.88) and middle (0.98) buds. It is very important to know the structural features of the buds in order to make the right pruning application suitable for the variety.

Anatomical Variation in the Fissurization of Lung with Embryological and Clinical correlations- A Case Report

Lungs are paired conical organs present in the thoracic cavity, which are responsible for gaseous exchange for oxygenation of blood. Both the lungs are divided into lobes by fissures. The right lung is divided into upper, middle and lower lobes by two fissures. The fissures are horizontal and oblique fissure whereas the left lung is divided into upper and lower lobes by oblique fissure. The left lung is divided into upper and lower lobe by oblique fissure. Both the lungs have ten bronchopulmonary segments (structurally separate and functionally independent units). Embryological evidence showed that the lungs developed from the endodermal counterpart of the foregut. Around 22 days of embryonic period, diverticulum are develop, then between 26-28 days lung buds develop. The right bronchial buds and left bronchial buds are branched into secondary and tertiary buds at 5th and 6th week of embryonic life consecutively. During routine anatomy dissection and demonstration in the Department of Anatomy, a 50 year old male cadaver showed anatomical variation in the right lung. The present study observed that the right lung showed partial horizontal fissure. The reason for partial or incomplete fissure formation is due to incomplete or absence of obliteration of prenatal fissure which indicates partial fusion of lobes, generally fissures separating the broncho-pulmonary segments in prenatal life. The reports says that incomplete fissures of the lung may lead to spread of infection like pneumonia to adjacent lobe and collapse in endobronchial lesions and gradation of the fissures of the lungs are very important for lung surgeries. The present study concludes that the knowledge of anatomical variation of lung is of utmost important in the field of pulmonary medicine.

Decapitation Experiments Combined with the Transcriptome Analysis Reveal the Mechanism of High Temperature on Chrysanthemum Axillary Bud Formation.

Temperature is an important factor that largely affects the patterns of shoot branching in plants. However, the effect and mechanism of temperature on axillary bud development in chrysanthemum remains poorly defined. The purpose of the present study is to investigate the effect of high temperature on the axillary bud growth and the mechanism of axillary bud formation in chrysanthemum. Decapitation experiments combined with the transcriptome analysis were designed. Results showed that the axillary bud length was significantly inhibited by high temperature. Decapitation of primary shoot (primary decapitation) resulted in slower growth of axillary buds (secondary buds) under 35 °C. However, secondary decapitation resulted in complete arrest of tertiary buds at high temperature. These results demonstrated that high temperature not only inhibited axillary bud formation but also retarded bud outgrowth in chrysanthemum. Comparative transcriptome suggested differentially expressed gene sets and identified important modules associated with bud formation. This research helped to elucidate the regulatory mechanism of high temperature on axillary bud growth, especially bud formation in chrysanthemum. Meanwhile, in-depth studies of this imperative temperature signaling can offer the likelihood of vital future applications in chrysanthemum breeding and branching control.

Secondary and tertiary budbreak release is enhanced by extended dormancy chilling in 'Shiraz' grapevines

Limited information exists regarding the dormancy of secondary and tertiary buds within the compound bud of grapevines. We were interested to evaluate how extended chilling duration would affect the budbreak percentage of all three bud orders within the compound bud. Dormant potted 'Shiraz' grapevines, with thirty retained buds per vine, were placed in a cool room at 4 °C over a 20-month period to extend dormancy. Vines were then systematically removed over five dates and placed in a controlled growth environment to assess budbreak percentages and cane tissue concentrations of abscisic acid and cytokinins. Budbreak was hastened by at least 13 d with vines receiving any extra chilling compared to no initial chilling. Furthermore, the firstly observed correlative inhibition of basal buds was apparently removed with chilling. Removal of correlative inhibition within the compound bud with increased chilling duration was also observed with the increases of secondary (doubles) and tertiary (triples) buds breaking simultaneously with the primary bud at each node. This resulted in 91 % of the nodes having two developing shoots and 56 % of the nodes presenting three developing shoots by the end of the experiment. Furthermore, a sigmoidal relationship between percent secondary buds and chilling duration was observed. Possible phytohormone connections were observed with the decline of ABA as secondary and tertiary buds broke at 414 d of chilling and depletion of the CKs, which coincided with the greatest rate of primary bud break after 242 d of chilling. Other possible involvement of ABA and Cis-type cytokinin interactions with secondary and tertiary bud dormancy is discussed. The results suggest future investigations into secondary and tertiary bud release within the grapevine using similar techniques may help to better understand the biochemical mechanisms associated with dormancy.

Effect of pruning strategy on 'Syrah' bud necrosis and fruitfulness in Brazilian subtropical Southeast

The change of wine grape harvest from wet season (summer) to dry season (winter) by changing the pruning management has improved quality of wines produced in the Brazilian Southeast. However, the vines need to be spur pruned twice a year, i.e. with a 1st pruning in August (winter pruning) for a vegetative cycle during the hot and wet summer, and a 2nd pruning in January (summer pruning) for a productive cycle during the cold and dry season. This double pruning strategy is made necessary by the fact that latent buds developed during the dry season cycle are not fruitful to support a productive cycle in the following year. This histological study, performed in the South of Minas Gerais State (Brazil), showed that annual single pruning done in the wet season (in January) displayed a high rate of necrosis on primary and secondary buds (bud necrosis – BN). In April, 99 days after summer pruning (DASP), the rates of BN were 40 % and 50 % at basal and apical node positions, respectively, reaching 80 % of BN in December (322 DASP). As a consequence of BN, bud potential fertility was drastically reduced from 0.5 inflorescence primordial (IP) per bud (in July) to 0.06 (in December) and bud burst in the next cycle from secondary and tertiary bud axes. Vines managed by double pruning system (submitted to summer and winter pruning) displayed a much higher fruitfulness potential, i.e. 1.46 IP per bud in December (112 days after winter pruning) and limited BN occurrence (20 %). On single pruned vines, we also observed a significant decrease of starch content in canes, trunks and roots. Internal bud anatomy showed that a random cell breakdown started 70 days DASP. At 211 DASP, all buds showed a large starch granule concentration, raphides and crystals of calcium oxalate inside idioblasts of leaf primordia and also in cortical parenchyma of the vegetative axis. The bud starch content was increased and a positive correlation between necrosis and starch accumulation was observed. The impact of carbohydrate availability on bud necrosis development was discussed. This study showed that the necrosis development towards secondary and tertiary axis of the dry season buds is the main reason of unfruitfulness in the vineyards managed by single pruning in the wet season, making the double pruning compulsory.

Karaerik Üzüm Çeşidinin Kış Gözlerindeki Soğuk Zararının Tarla ve Laboratuvar Koşullarında Belirlenmesi

This study was conducted to detect cold damage in dormant buds of grapevine under field (by shooting test) and laboratory (by sectioning method) conditions. In the determination of the low temperature damage, it has been investigated whether there is a difference between the method of sectioning in laboratory conditions and the real shooting level in the field conditions . The study was carried out in the vineyard which was established with the Karaerik ( V. vinifera L. ) grape cultivar in the Uzümlü district of Erzincan in 2012, 2013 and 2014. Samples of an old grapevine cuttings from the vineyard was transported to the laboratory on the same day and sections were taken in order to determine the damage level. Cold damage was assessed based on 1-4 bud averages. In addition, cold damage was evaluated separately in 1st, 2nd, 3rd and 4th nodes. The mortality rates of primary and secondary buds for the first 1-4 buds average were determined and the vitality rates of tertiary buds were determined in order to determine the ultimate vitality. At the second stage of study, the mortality rates (%) of primary and secondary buds and the viability rates (%) of tertiary buds were determined by counting in spring the shoots come from the primary, secondary, and tertiary buds of the first 4 buds that were left in pruning in vineyard. Secondary and tertiary buds were also considered alive if the primary buds have sprouted in vineyard. In the study that determined the level of damage of the buds, it was found that the difference between the sectioning method and the shooting test was 7.9% in primary buds, 14.56% in secondary buds, and 0.1% in tertiary buds . The mortality rates of primary buds and the viability rates of tertiary buds were found statistically insignificant differences between the methods, but the mortality rates of the secondary buds were found statistically significant differences between the methods.

Studies on the effect of media on sucker production of banana cv. POOVAN

In vivo macropropagation is an alternative simple and cheap technique for banana multiplication. The experiment was conducted in Completely Randomized Design with 13 treatments in three replications. The treatments consisted of three growing media (FYM, Rice hull, Sawdust), two biofertilizers ( Azospirillum and VAM) with sand alone as control. Observations on the production of primary, secondary and tertiary buds was recorded. The results of the study revealed that use of FYM + VAM (T 7 ) as growing media resulted in increasing the primary, secondary and tertiary bud regeneration. The time taken for emergence of primary, secondary and tertiary buds was also earlier in the treatment T 7 (FYM + VAM).

Macro-propagation of dwarf Cavendish banana

Effect of growing media on macro-propagation of dwarf Cavendish banana was studied in an experiment conducted during 2012 to 2014 at the Farm, Department of Horticulture, Assam Agricultural University, Jorhat, Assam. The experiment was laid out in completely randomized design with three replications under ploy house condition. Evaluation of macro-propagation practice using sawdust as initiation media, supplemented with various biofertilizers resulted in highest number of uniform sized tertiary bud production when the decorticated corm cavity was poured with 40 ppm BAP (4 ml) and the media was supplemented with Bacillus subtilis alone and along with VAM. This treatment also performed better regarding shortest time requirement for production of first primary bud and total number of tertiary suckers, and other vegetative growth characters.

Preventing spring freeze injury on grapevines using multiple applications of Amigo Oil and naphthaleneacetic acid

‘Edelweiss’ is an important grape cultivar grown in the Midwestern part of the USA. It is one of the earliest cultivars in the vineyard to break bud, making it very susceptible to late spring freezes. ‘Edelweiss’ primary buds produce a significant amount of fruit, while unlike many other hybrids, the secondary and tertiary buds will have little to no yields, thus making it important to protect the primary buds from a late freeze. The objective of this research was to determine if multiple applications of Amigo Oil or naphthaleneacetic acid (NAA) achieve a greater bud delay when compared to single applications. ‘Edelweiss’ vines were treated in January, January and February or January, February and March. Amigo Oil was applied at 10% (v/v) and NAA at 1000 ppm with a custom built all-terrain vehicle (atv) sprayer. All treatments of oil led to a significant bud break delay ranging from 1 to 8 days as compared to the control. None of the treatments were phytotoxic to buds or negatively affected yield or fruit characteristics. Grape growers in climates with the potential of late spring freezes may consider the use of Amigo Oil or NAA as a potential means to protect their vines from freeze injury.

STUDY ON FLOWER BUD MORPHOLOGICAL DIFFERENTIATION OF 'TIANXIANG' STRAWBERRY

Flower bud differentiation is very important for the yield and quality of strawberry fruit. In order to identify flower bud development, the paraffin section method was adopted to observe the morphological differentiation of apical meristems of ‘Tianxiang’ strawberry (Fragaria A— ananassa Duch.) runner plants in Beijing, 2009. The results showed that top flower bud differentiation lasted for about 44 days, might be divided into seven stages. On 15 September, the buds came into the primary differentiation stage, the apical points became semi-circular, broader, and nearly 70% of the buds started differentiation on 20 September. Then the inflorescence primordia were visible on the apical points, and about 60% of the buds went into the inflorescence primordium differentiation stage on 25 September. Thereafter, the sepal primordia appeared at the base of inflorescence primordia, 60% of the buds were in the sepal primordium differentiation stage by 1 October. On 6 October, in about 90% of the buds the petal primordia could be seen inside of sepal primordial. About 10 d later, the stamen primordia developed in around 80% of the buds. On 22 October, the pistil primordia appeared on the surface of the receptacles. The main pistil primordium differentiation stage was from 22 to 29 October, and about 70% of the buds had finished their pistil primordium differentiation on 29 October. At the end of sampling on 29 October, the secondary buds were mainly in the stamen primordium differentiation stage, and the tertiary buds were mainly in the petal primordium differentiation stage. Our results provided the details of flower bud development in ‘Tianxiang’ strawberry in Beijing, which will contribute to its production and management.

English

fetuses of varying gestational ages, ranging from 33m.m C.R.L. to 270m.m.C.R.L. (i.e. from 8weeks to 32weeks of intrauterine life) were studied to note the developmental sequence of mammary gland. Tissues were prepared for microtomy by Paraffin wax embedding method. Serial sections were stained by Haematoxylin & Eosin (H & E) and Masson's Trichome method(1). It was observed that the organ is subject to fluctuations in its development. In the present study the primary bud, secondary bud, & tertiary bud formation is seen at11th week ,14th week & 18 th week of gestation respectively .The canalization appeared at 20 th week of gestation. Variation is seen in the mode of canalization as well as in the time of start of canalization. In the present study an endeavour has been made to establish the time of appearance of mammary buds and their time of canalization .The observations are compared with the findings of other workers and discussed in the light of literature. Mammogenesis or development of mammary gland is of great importance for anatomists, surgeons, pathologists, physicians, obstetricians etc. A large number of developmental anomalies like amastia, athelia, polymastia, polythelia, etc are of interest to them which can be understood more if thorough

Effects of harvest date, wilting and inoculation on yield and forage quality of ensiling safflower (Carthamus tinctorius L.) biomass

Safflower (Carthamus tinctorius L.), usually grown as a source of oil crop, can be used as fodder either for hay or ensiling purposes, particularly in semi-arid regions. A 2-year trial was conducted in southern Italy to evaluate the production and forage quality of safflower biomass cv. Centennial, harvested at three different stages: 1, at complete appearance of primary buds (PB); 2, at complete appearance of secondary and tertiary buds (STB); and 3, at 25% of flowering stage (FS). For each stage of growth, 50% of the biomass was ensiled in 4 L glass jars without and with inoculation (Lactobacillus plantarum, LAB), and the other 50% was field wilted for 24 h before ensiling. Dry matter (DM) content and yield (DMY), pH, buffering capacity (BC) and water soluble carbohydrates (WSC) were determined on fresh forage. On safflower silages were also evaluated ammonia-N, crude protein (CP), fibre fractions, fat, lactic and acetic acids, Ca and P, and gas losses. DMY ranged from 4.5 t ha(-1) (PB harvesting) to 11.6 t ha(-1) (FS harvesting). DM content varied from 129 g kg(-1) (PB not wilted) to 630 g kg(-1) (FS wilted). The WSC in forage before ensiling with not wilting ranged from 128 (PB stage) to 105 and 100 g kg(-1) DM at STB and FS stages, respectively. The wilted safflower forage showed a lower WSC compared to wilted forage. The high sugar substrate allowed lactic acid fermentation and a good conservation quality in all the harvesting stages. Silages quality was strongly influenced by the treatment performed. Wilting practice increased DM, pH and NDF contents but reduced lactic acid, acetic acid and NH(3) -N values. Inoculation reduced DM, pH and NDF contents, but increased lactic and acetic acids, CP and ash. As result, wilting the forage for 1 day was very effective in the early harvesting stage because this practice significantly increased DM, reducing on the same time the intensive fermentation and proteolysis processes of silage. When harvesting is performed at the beginning of the flowering stage wilting is not necessary.

Compensatory Ability of Strawberries to Bud and Flower Removal: Implications for Managing the Strawberry Bud Weevil (Coleoptera: Curculionidae)

The strawberry bud weevil, Anthonomus signatus Say, is considered a major pest of perennial matted row strawberry plantings in the eastern United States with an economic threshold of 2 clipped buds per meter row. No relationship was found between the number of naturally clipped buds per meter (range, 0–20) and subsequent yield over 2 field seasons for the strawberry cultivar ‘Earliglow’ indicating the potential for compensatory fruit production. In field experiments, flower buds or open flowers were removed by hand and the impact on yield for 3 strawberry cultivars measured. For the cultivar ‘Jewel’, removal of all primary or secondary buds did not result in a significant decrease in yield relative to control plots, although the removal of all tertiary plus higher order buds did result in a significant decrease. For ‘Seneca’ and ‘Kent’, removal of all primary, secondary, or tertiary buds did not significantly decrease yield compared with control plots. Compensation to bud removal was achieved by increasing fruit weight of remaining buds and increasing the number of higher order buds matured. When similar treatments were applied to flowers, we observed a negative impact on yield for all 3 cultivars. In 1996 we assessed the benefit of treating for strawberry bud weevil when injury reached the economic threshold at 7 commercial strawberry operations in upstate New York. Untreated plots had significantly more clipped buds per meter than treated plots (13 versus 4), however, there was no difference in yield.

Thermotolerance of Dormant and Actively Growing Cabernet Sauvignon Is Improved by Heat Shock

Actively growing Cabernet Sauvignon plants grown at 25°C were given a four-hour heat shock at 40°C, followed by a four-hour incubation period at 25°C. The heat shocked plants, when compared to non-heat shocked plants, had less leaf damage, tissue water loss, and electrolyte leakage after exposure to 50°C. Dormant Cabernet Sauvignon cuttings were removed from 3°C cold storage and heat shocked for 30 minutes at either 45°C or room temperature (23°C). This was followed by a four-hour incubation period at room temperature. A group of non-heat shocked control cuttings were held continuously at 3°C. Thermotolerance was tested by placing the cuttings in water baths at 54°C, 56°C, 58°C, or 60°C for 30 minutes. Primary, secondary and tertiary bud survival, time required for buds to begin growth, and root vigor were evaluated for each treatment. Bud survival was high in all treatments at 54°C and 56°C, while at 60°C there was 100% bud mortality in all treatments. At 58°C, however, cuttings that were heat shocked at room temperature were significantly (<i>p</i> &lt; 0.01) more thermotolerant than the control cuttings, and those that were heat shocked at 45°C were significantly (<i>p</i> = 0.01) more heat tolerant than those heat shocked at room temperature. These results show that both dormant and actively growing grape tissues respond to heat shock treatment by increasing their thermotolerance. To our knowledge, this is the first time that heat shock responses have been shown to occur in dormant woody plant tissue. Heat shock treatment could lead to more effective pathogen elimination by allowing grape propagation material to be treated at higher temperatures than are currently possible.

094 CROPLOAD EFFECT ON BUD COLD HARDINESS OF Vitis labruscana L. cv. CONCORD

An increase in mechanical pruning of Concord grapevines in Washington has led to a marked increase in yield. In 1993 the average yield for the 20,000 plus acres was slightly greater than 12 ton/acre. As part of a long term study, initiated in 1987, to evaluate the effects of mechanical pruning on Concord yield and fruit quality, we have also followed bud cold hardiness and winter injury over several years. Cold hardiness was monitored using low temperature exotherm analysis of excised buds. Winter injury was evaluated by visual examination of bud and cane tissues collected from vines with different croploads. In 1990 the average yield for mechanically pruned vines was 13T/ac and for balance pruned vines about 8T/ac. Winter injury during December 1990 showed significantly less injury to mechanically pruned vines whether primary, secondary or tertiary buds were examined. During the winter of 1991-92 and 1993-94 bud cold hardiness of individual vines showed no relationship to cropload per vine.

396 CALLA LILY VEGETATIVE &amp; REPRODUCTIVE DEVELOPMENT PATTERNS

The release of latent buds (adaptive reiteration) and aerial shoot architecture of the rhizomatous calla lily plant has been researched for pot production. Rhizome mapping has explicitly shown vegetative and floral bud positioning in relation to tissue growth and expansion. Floral initiation normally occurred only on the mother portion of rhizomes. Gibberellic acid (GA3) application enhanced this phenomenon and caused initiation on daughter ramets. Bud excision performed at planting through Day 16 microscopically revealed lack of floral initiation in dissected meristems prior to planting, transition by Day 4, elongation beginning at Day 8 and `small to medium sized spadixes present by Day 12 and 16. Floral development was similar in treated and untreated primary buds, but delayed in secondary and tertiary buds with elongation occurring by Day 16. Pretreatment of GA3 prior to planting revealed spadix presence at Day 0. Floral development correlated with ramet size showed most flowers on largest ramets but formation on all sizes with GA3 treatment. GA3 also caused increased vegetative bud formation on rhizomes.

Inflorescence and flower development in Costus scaber (Costaceae)

The inflorescence of Costus scaber terminates an erect axis of a sympodial rhizome system. Primary bracts are borne on the inflorescence in spiral monostichous phyllotaxy. One-flowered cincinni occur in the axils of these bracts. Each cincinnus consists of an axis bearing a terminal flower and a secondary bract on the anodic side of the flower. A tertiary bud forms in the axil of this bract but does not complete development. The inflorescence terminates by cessation of growth of the apex and precocious development of the primary bracts. Floral organs are formed sequentially beginning with the calyx, and continuing with the corolla and inner androecial whorl, outer androecial whorl, and gynoecium. All flower parts, except for the calyx, originate from a ring primordium. Regions of this primordium separate to form the corolla and inner androecial members. It was not possible to determine the sequence of androecial member formation. The labellum is composed of five androecial members, three from the outer whorl and two from the inner. The third member of the inner whorl forms the stamen and its petaloid appendage. The gynoecium forms from three conduplicate primordia. The margins of two of these primordia are the product of phyietic fusion.

Deep Supercooling of Dormant and DeacclimatingVitisBuds

Differential thermal analysis was used to measure deep supercooling in dormant buds of 15 <i>Vitis vinifera</i> L. cultivars, <i>V. labruscana</i> Bailey cv. Concord and four <i>Vitis</i> hybrids. The primary, secondary and tertiary buds in each compound bud produced discrete low temperature exotherms (LTE9s). In singlebud experiments with White Riesling the largest LTE9s originated from the primary buds. The temperature of the median low temperature exotherm (LTE₅₀) increased about 11°C in White Riesling from late winter to early spring but increased 14°C in Concord and over 16°C in the French hybrid Chelois over the same period. These LTE₅₀ increases are consistent with the characteristic deacclimation patterns of White Riesling and Concord buds. The LTE₅₀ of White Riesling bud samples in late winter was within 1°C of the temperature which killed 50% of the buds under programmed freezing.