Number Of Vegetative Buds Research Articles

Role of key flowering genes in Prunus dwarfing rootstocks

Although Spain is placed as the third almond producing country worldwide after USA and Australia, planting design has recently made a drastic change towards high-density planting system using low vigour rootstocks. This represents an important challenge in order to understand how the trees develop and how different cultivars and rootstocks adapt to these modern planting systems. In this work, we carried out a phenotypic study by using several combinations of rootstock/scion in a commercial orchard. For phenotyping we monitored four traits in order to search for tree development: TCSA (Trunk Cross-Sectional Area), shoot length, number of flower buds and number of vegetative buds.

INFLUENCIA DEL USO DE REGULADORES DE CRECIMIENTO SOBRE BROTES VEGETATIVOS Y NÚMERO DE ESTRÓBILOS MASCULINOS EN <i>Pinus pinea</i> L. EN CHILE

La utilización de reguladores de crecimiento o fitorreguladores, es una alternativa para aumentar la floración en la familia Pinaceae. En este estudio se analizaron los efectos de la aplicación de reguladores de crecimiento (fitorreguladores) sobre brotes vegetativos y estróbilos masculinos de Pinus pinea L. Los productos seleccionados fueron: giberelina cuatro más siete (GA4+7), ácido naftalenacético (NAA) y bencilaminopurina (BAP), distribuidos en siete tratamientos, incluido el control. Estos fitorreguladores se emplearon en una plantación de Pinus pinea de 16 años de edad ubicada en Toconey, comuna de Pencahue, región del Maule-Chile. Los tratamientos se aplicaron en cinco fechas, cada dos semanas (fin de agosto a inicio de noviembre). Al final de las aplicaciones se evaluaron las variables: estróbilos masculinos, número de brotes vegetativos y de nuevas brotes, y longitud de brotes apicales. Los principales resultados indicaron que la aplicación de 1.000 mg L-1 de GA4+7, fue el tratamiento que indujo la mayor floración masculina, presentando un 99,6 % más de estróbilos con respecto a las ramas testigo y también tuvo un efecto significativo en la longitud de los brotes apicales, aumentando más del doble la longitud respecto al testigo. En el número de brotes vegetativos, la aplicación de 500 mg L-1 BAP mostró diferencias significativas, obteniendo un incremento de 414,3 % con respecto al tratamiento control.

Flowering and fruiting phenology, and physico-chemical characteristics of 2-year-old plants of six species of Opuntia from eight regions of Morocco

SUMMARYWe have described the flowering and fruiting phenology of 14 accessions of six Opuntia species grown in Morocco: O. ficus-indica, O. robusta, O. aequatorialis, O. dillenii, O. leucotricha, and O. stricta. We also determined the physicochemical characteristics of their cladodes. For each accession, we used four-to-20 plants. Two systems were used to measure phenology: the extended Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie (BBCH)-scale and the National Phenology Monitoring System. Five principal stages were described: the development of vegetatively-propagated organs (vegetative buds), the development of flower buds, flowering, fruit development, and fruit maturity. The number of vegetative buds varied significantly among the 14 accessions, while only four accessions produced flower buds. After reaching their final size, fruit lengths varied from 3.40–6.40 cm, while fruit diameters varied from 1.93–3.90 cm. The average cladode number differed significantly among genotypes and varied from 1.75–7.75. There were also significant differences in cladode length (13.75–30.63 cm), width (6.25–17.33 cm), thickness (0.65–1.38 cm), fresh weight (FW; 67.50–766.00 g), and dry weight (DW; 8.75–67.15 g) between species. Water content and ash content, as well as total protein and total sugar concentrations, showed significant differences and were within the ranges of 86.67–92.04% (w/w), 12.97–22.08g 100 g−1 DW, 4.64–11.56g 100 g−1 DW, and 3.22–12.51 g 100 g−1 DW, respectively. Our results will help in the development of agronomic management practices and improve the characterisation, valorisation, and use of cactus pear species grown in Morocco.

Morphological properties of fruit bearing shoots of apricot cultivars

Morphological properties of fruit bearing shoots: length, number of flower buds and vegetative buds and their ratio were studied in 20 apricot cultivars during a two-year period. Control cultivar for comparison was ?Hungarian Best? (?Magyar kajszi?), clone 235. Fruit bearing shoots of apricot were classified into three groups: shoots, sylleptic shoots and spurs. The average length of shoots ranged from 68.8 to 85.0 cm; of sylleptic shoots from 6.9 to 27.0 cm; and of spurs from 1.4 to 4.1 cm. Flower buds/vegetative buds ratio was higher in spurs and sylleptic shoots (2,5 on average), compared to shoots (1,8 on average). Most of the studied apricot cultivars are characterized by higher flower bud density compared to control cultivar (?Hungarian Best?), indicating their higher yield potential. For all studied traits statistically significant differences between cultivars were found. The great variability was found in length of shoots, number of flower buds, and number of vegetative buds, while small coefficients of variation were found in thickness of shoots and length of internodes. Based on the obtained results, recommendations for pruning can be made. Cultivars with a higher number of flower buds (per 1 m in length and in relation to vegetative buds) such as: ?Lenova?, ?Tomcot?, ?Veecot?, ?Ninfa?, ?Sophia?, ?Silvercot? and ?Goldrich? require severe pruning. On the other hand, cultivars with lower flower bud density e.g. ?Hungarian Best?, ?Cegledy Arany? and ?Bella d?Imola? can be pruned slightly.

Cultivar-by-cutting height interactions in Napier grass (Pennisetum purpureum Schumach) grown in a tropical rain-fed environment

A field study was conducted in Thailand under a rain-fed environment to determine the effect of four different cutting heights above ground level and two closing dates on dry matter (DM) production, yield components, and fodder quality of five different cultivars of Napier grass (Pennisetum purpureum Schumach), all treatments cut with the same frequency of approximately 4 weeks. Eighteen quantitative trait measurements were used to investigate the interactions between cultivar diversity and cutting regimes. Principal-component analysis (PCA) showed a clustering of two distinct cultivars and another group of cultivars in one cluster without obvious structure. There was also a clear clustering of the control (0 cm cutting height) across all cultivars whereas other cutting heights affected growth differently according to cultivar. The optimal cutting regime for obtaining high DM yield depended on the genetic background and did not relate to a reduction in the number of vegetative buds for the cultivars with a basal shooting pattern. For the cultivars with higher DM yield arising from high stubble height, the DM was differently distributed into leaf and stem material. Before cuttings, the tiller number was reduced in the control plots but not in the plots with more lenient cutting height. Average tiller yield increased with increasing cutting height to reach a maximum at 20-cm cutting height. Average harvested culm length was constant for the four cutting heights. The variation in a number of plant traits, arising from cultivar diversity, can be altered by agronomic practices, thereby causing potentially contradictory results. Defining specific interactions of cultivar-by-cutting height treatments and analysing these with PCA proved to be a useful approach for visualising clusters from multiple measurements. The proposed approach for analysing data could serve as a model for other trials with similar interactions between cultivar diversity and agronomic treatments.

Architectural traits of fruiting shoots in Juglans regia (Juglandaceae) related to fruiting habit and environmental conditions

The objective of the present study was to compare some basic architectural traits of annual shoots (1YS) in common walnut (Juglans regia L.), and to evaluate the impact of extreme drought and heat on the fruiting and growing response of the annual shoots. Measurements were conducted on three cultivars that have a terminal-bearing fruiting habit (Franquette), intermediate fruiting behaviour (Zdole-59) and a lateral-bearing fruiting habit (Fernor). Across 3 years, the mean 1YS of Franquette were one-third longer than those of the other two cultivars and their mean basal diameter was larger than that in Fernor and almost equal to that in Zdole-59. For Franquette, the length : diameter ratio showed a slender shoot morphology, whereas the shoot morphology was more compact in Fernor and Zdole-59. The 1YS of Franquette and Fernor had equal fruiting potential, with 2.8 and 2.7 fruits per shoot, respectively. Short but thick 1YS with the highest number of vegetative buds indicated dense branching and the good growing capacity of Zdole-59. The number of vegetative buds per 1YS changed during the 3 years in all cultivars, whereas the number of flowering buds per 1YS did not change in Franquette. Extreme dry and hot weather during the spring and summer of 2003 caused a reduction of 35–58% in length and a reduction of 2–16% in the basal diameter of the 1YS, regardless of fruiting behaviour. In the less vigorous, but highly productive lateral-bearer Fernor, unsuitable weather conditions in 2003 affected flower differentiation and resulted in significantly fewer fruits in 2004. The mean daily temperature in the period March–August was negatively correlated with the 1YS diameter and the number of vegetative buds per 1YS, whereas the mean precipitation during the same period showed a positive relationship with the length and diameter of the 1YS. Information obtained through shoot-architecture analysis could be useful in cultivar choice for new orchards, especially at a time of great climatic changes. Simple predictions for further development of the annual shoots could also be made.

Plasticity in bud demography of a rhizomatous clonal plantLeymus chinensis L. in response to soil water status

We surveyed the bud demography ofLeymus chinensis L plants along a soil-moisture gradient that was caused by a flood in 1998 on the Song-nen Plain in northeastern China. The number of vegetative buds per ramet was influenced by soil water content, with regression curves being quadratic and the opening of the parabola pointing downward. In addition, the optimum regression models for the numbers of rhizomatous buds and tiller buds relative to soil water resulted in a quadratic parabola and exponential curve, respectively. Vegetative buds flourished between August and October, with plants producing more of those buds on flooded plots than on control sites. The number of rhizomatous buds per ramet was much higher than for tiller buds throughout most of the growing season, and production of the former was more apt to be affected by soil water status. This observed superiority of rhizomatous bud production was thought to be a consequence of the whole-plant adjustment that was stimulated by an abnormally high moisture content. It could also be interpreted as a strategy for “escape” from disadvantageous overly wet conditions. Moreover, the position-based preference for bud emergence along the ramets could be an underlying mechanism for selective ramet placement.

Exotic woody invader limits the recruitment of three indigenous plant species

The demographic response of indigenous plants to the invasion of exotic woody plants has rarely been quantified, however, could be beneficial to restoration efforts. We determined which life history stages of three indigenous plants: Correa alba var. alba (Rutaceae), Monotoca elliptica (Epacridaceae) and Lomandra longifolia (Lomandraceae), were most affected by the invasion of Chrysanthemoides monilifera spp. rotundata (bitou bush) on the eastern Australian coast. We also assessed whether various morphological and physiological parameters of the mature stage of these species were affected by the presence of bitou bush. Populations of all three indigenous species in bitou bush invaded habitats had significantly fewer small individuals and lower population density than those in non-invaded habitats. The mean flower production, number of vegetative buds, and physiological stress of the mature stage of each of these species in bitou bush invaded habitat did not differ from those present in the non-invaded habitat. We therefore propose that bitou bush affects indigenous plant populations primarily by preventing recruitment through the germination or seedling growth stages. The reduction in indigenous plant recruitment creates spaces that are likely to facilitate bitou bush monoculture formation in the new host environment. Planting of established juvenile plants is suggested to assist in the restoration of bitou bush invaded areas.

Stability of the annual shoot diameter in Persian walnut: a case study of different morphotypes and years

The basal diameter of the annual shoot (1YD) affects vegetative growth and fruiting of the walnut trees. In order to determine interdependency between the 1YD and the older parent wood, 64 walnut genotypes belonging to four different branching and fruiting habits (morphotypes M-I, M-II, M-III and M-IV) were investigated. Year-to-year stability of 1YD was tested with the architectural analysis of a 3-year-old fruiting branch and its constituents (a 3-year-old bearer + corresponding 2-year-old + annual shoots) during 3 successive years. Based on Pearson's correlation coefficients and the multiple regression analysis of 12 quantitative traits, 12 models (four morphotype in 3 successive years) of 1YD were formed. They were compared with the standard model which was calculated on the basis of 1-year measurements of 1Y with no respect to the branching and fruiting type and comprises three quantitative traits, i.e. basal diameter of a 2-year-old parent shoot (2YD), the length of 2Y shoot (2YL), and the length of annual shoot (1YL). In a single year, the 1YD was influenced by two–five parameters. Five out of 12 models agreed with the standard model: in the lateral fruiting genotypes (M-IV), 1YD was always under the influence of the 2Y diameter, and the 1Y length. In addition, the number of nodes of the 2Y parent shoot had an important influence on 1Y diameter. In the terminal bearers (M-I), the impact of 2YD on the 1YD slightly increased with the tree age, and some other parameters, like 1Ynumber and 1Ynodes, which became to be important for 1YD. In the intermediate genotypes with mezotonic ramification (M-II), the number of vegetative buds per 1Y and angles of 1Y had significant effects on 1YD. In the intermediate bearers with acrotonic ramification (M-III), one to four other parameters were included into the model each year beside the 1Y number. Since the traits of a 2-year-old parent shoot have a great influence on the 1YD, the information from the year N can be used for the prediction of the annual shoot development in the year N+1. Such a prediction is more reliable in M-I and M-IV than in M-II and M-III. When we deal with the intermediate fruiting cultivars, 1Y number has to be considered in prediction of 1Y diameter beside 2YD and 1YL.

Growth dynamics and reproductive activity of annual shoots in the walnut cultivar 'Elit'

An architectural analysis of a fruiting branch in the Slovenian variety 'Elit' was conducted during three successive years. The fruit bearing branch was constructed of a three-year-old parent shoot plus all corresponding two-year-old shoots and annual shoots (1Y). The construction of the bearing branch during the time caused a statistically significant increase in the number of annual shoots. The basal diameter and the length of 1Y significantly depended on a year whereas their angles did not. In spite of decreasing length of 1Y, the number of vegetative buds per shoot increased from the first to the third year of observations. The number of nodes was closely correlated with the length of the shoots. Activity points on the 1Y were most often on the apical two or three nodes, what was expressed by a marked acrotony. The number of active points varied as the tree matured. The ratio fruit bearing 1Y / total 1Y was 0.47 in year 1; 0.18 in year 2; 0.74 in year 3. It points to the slightly alternance. As the tree grew the number of flowering buds per 1Y as well as the number of female flowers per 1Y increased. The results of the three-year-long research show some growth and development rules in the walnut cultivar ‘Elit’, however, they do not allow a reliable prediction of the following activities. We assume that this will be possible after another three-year-long analysis, with the help of the Hidden Mark Model.

How does spittlebug oviposition affect shoot growth and bud production in two willow species?

We measured the effects of oviposition by the spittlebug Aphrophora pectoralis on shoot growth and bud production in two willow species, Salix miyabeana and Salix sachalinensis. In autumn, adult females of A. pectoralis insert their ovipositor into the apical region of 1‐year‐old shoots, resulting in the death of most shoot tips within 1 week. Consequently, an increase in the number of dead buds and a decrease in the number of vegetative buds on 1‐year‐old shoots was recorded. In the following spring, the growth of current‐year shoots was greatly increased on 1‐year‐old shoots damaged by spittlebug oviposition. Furthermore, spittlebug oviposition increased the production rate of vegetative buds in both S. miyabeana and S. sachalinensis. However, no impact on the production rate of reproductive buds was detected in either willow. We conclude that the compensatory growth of current‐year shoots and an increase in vegetative buds in the two willow species was caused by oviposition of A. pectoralis.

Direct shoot bud formation from leaf explants of seedlings and mature mangosteen ( Garcinia mangostana L.) trees

Abstract This paper reports the direct regeneration of shoot buds from leaf segments of mangosteen (Garcinia mangostana L.) cultured in vitro. Explants were taken from 1–3-year-old seedlings and 16 year-old mature fruiting trees. The optimal level of benzylaminopurine (BAP) for shoot bud development from seedling leaf explants was 5 mg l−1. Higher concentrations were also effective but shoot buds were clustered and stunted. Very young red leaves, 2–3 cm long, from mature trees also produced shoot buds on this medium. When leaves from mature trees that had turned from red to green were used, the frequency of shoot bud formation decreased. The number of vegetative buds was higher in red leaves from seedlings compared with young red leaves from mature trees. Secondary shoot buds also developed on leaves of cultured epiphyllous shoots from both seedlings and mature trees. Shoots from leaves of seedlings and mature trees, measuring more than 2 cm were rooted with an acute auxin treatment. Plantlets from seedling leaf explants were successfully acclimatised and established in soil.

Response of orchard 'Washington Navel' orange, Citrus sinensis (L.) Osbeck, to saline irrigation water. I. Canopy characteristics and seasonal patterns in leaf osmotic potential, carbohydrates and ion concentrations

Effects of irrigation water salinity on tree canopy volume, leaf area, rates of leaf abscission and production, as well as seasonal patterns in leaf osmotic potential (=), starch, soluble sugars and sodium and chloride concentrations were determined for 24-year-old 'Washington Navel' orange trees (Citrus sinensis [L.] Osbeck) on sweet orange (C. sinensis) rootstock. Trees had been irrigated with water containing either 5 or 20 mol NaCl m-3 for 5 years prior to measurements.Trees irrigated with 20 mol NaCl m-3 had a greater number of vegetative flushes in spring. This occurred at the expense of flowering, as numbers of reproductive and mixed flushes were reduced by salinity. Despite a high number of vegetative buds on trees irrigated with 20 mol NaCl m-3, leaf area was still less than low salinity trees.Extensive abscission of spring flush leaves occurred from mid-summer onwards for trees irrigated with 20 mol NaCl m-3. This was not a consequence of leaf water deficit, as more negative leaf osmotic potentials resulting from increased foliar sodium and chloride concentrations resulted in maintenance of leaf turgor. Excessive concentrations of sodium and/or chloride may have been responsible for abscission observed. Some acclimation of foliage to salinity was evident.Irrespective of salinity treatment, leaf osmotic potential became more negative as the season progressed. This was partly due to increased concentrations of soluble sugars in foliage during autumn and winter. Levels of soluble sugars and starch were consistently lower in leaves on trees irrigated with high salinity water, indicating that production rather than utilization of carbohydrate may limit citrus productivity under saline conditions.