Impact of environmental changes (temperature and RH) on reproductive biology in Duranta repens (Verbenaceae) growing at ten different sites of Agra was studied. It flowers throughout the year, with optimum flowering in September. The flowers are arranged in loose clusters on terminal or axillary racemes. They are either blue or lavende...r in colour, hermaphrodite, actinomorphic and complete. The plants exhibit floral polymorphism (increase and decrease in number of petals and stamens) and considerable variation in extent of pollen fertility, floral density, insect pollinators and fruit-set percentage. The changes in temperature and relative humidity during the entire flowering period, was found associated with the variation in floral structure, pollen fertility and fruit-set percentage. Based on the percentage of fruit-set during different seasons of a year, there were three distinct periods, namely maximum, moderate and minimum periods. The present paper deals with the comparative view of reproductive biology of this ornamental plant in these periods. During the months of August—November when temperature ranges between 13.7-36.6 °C and RH between 79-89% the plant exhibits maximum fruit-set percentage (68-85%). This was associated with maximum flowering, increase in floral size, and increase in visitation rates of pollinators and higher degree of pollen fertility. On the other hand, with temperature reaching to the maximum (15.1-41.5 °C) and reduction in RH (14.1-41.3%), the percentage of fruit-set was reduced to the minimum (21-30%). During this period, number of flowers/plant, floral size, pollen fertility, visitation rates of pollinators were reduced to the minimum. During this period floral polymorphism was also 'recorded.
The modern nursery industry requires seed sources of a high quality and regular quantity year by year. Besides the seed sources of processed cultivars (Bartlett pear, Shipley, Elberta peach) special seed orchards are planted with selected seed trees producing high quality and genetically determined seed (hybrid seed or inbred lines). Seedlings...are still the most common commercial source of rootstocks for stone fruits (almond, apricot, peach, plum, prune and walnut). Although clonal rootstocks are spreading, usage of seedlings is still predominant at stone fruits and nuts. For successful seed production and planning of seed orchard the knowledge on floral biology, flower fertility, pollination, blossom time of trees (selected clone or cultivars) used for seed production is essential. In this field very little systematic research was carried out most of the papers were published in the second half of the 20th century. Our mini review gives an overview on the importance of flower fertility in the mating systems applied in seed orchards, and the research results on floral biology of fruit tree rootstocks propagated by seed (Prunus avium, Prunus mahaleb, Prunus armeniaca, Prunus cerasifera, Prunus insititia, Prunus amygdalus, P persica, P amygdalopersica, Pyrus pyraster, Pyrus communis and Pyrus betulifolia) over the last decades.
Floral biological characteristics that may influence cultivar susceptibility to fire blight were studied in 10 pear cultivars in two Hungarian orchards from 1999 to 2003. The receptaculo-ovarial, automorphic nectary is usually bigger in tolerant cultivars than in susceptible ones. Nectary stomata are meso- or xeromorphic. Susceptible cultivars...tend to have more xeromorphic stomata, where guard cells are located 1-3 cell rows below the epidermis. The size of nectar chambers is usually smaller in susceptible cultivars. Floral nectar, consisting mainly of glucose and fructose, is more abundant and less concentrated if the cultivar is susceptible to fire blight. The amount of chlorogenic acid was higher in the flowers of tolerant cultivars than in susceptible ones.
Several species in the Lamiaceae family are therapeutically significant medicinal plants. Such as sage (Salvia officinalis L.), rosemary (Rosmarinus officinalis L.), peppermint (Moldier piperita L.). marjoram (Majomna hortensis Winch), thyme (Thymus vulgaris L.), Origanum spp., hyssop (H...yssopus officinalis L.), Lavandula spp., basil (Ocimum basalicum L.), lemon-balm (Melissa officinalis L.) are regularly produced in Hungary. Nevertheless, data on their floral biology are not satisfactory. This review intends to gather information on the characteristic constitution of flowers and inflorescences, blooming dynamics, pollination mechanism and crossability of some of the most significant medicinal and spice species
Flowers are mainly hermaphrodite, however, also monoeceous ones are turning up: pistillate flowers marjoram, tyme, oregano. In flowering of a plant individual, a basipetal blooming sequence is described. These species have a floral structure fully adapted to pollination by insects, and the majority of them is an excellent honey-plant (lavandel, hyssop, sage, etc.).
Flowers exhibit characteristic proterandry, therefore autogamy is considered to be almost impossible, and geintonogamy as well as xenogamy to be the most characteristic ways of fertilization. However, in several cases self-fertilization proved to be also successful. Crossability among cultivars or species is depending on the genotype combination and usually produces less seed than the above forms of fertilization.
Pál Maliga founded the Hungarian research in floral biology of fruit species during his more than forty-year-long carrier. Almost all pome and stone fruit species have been covered by his activities, but he also dealt with the fertility of walnut and chestnut. Regularities have been revealed and the methodical studies opened the way to approac...h and elaborate alternatives for the association of varieties in planning high yielding commercial plantations. In his breeding activity the choice of crossing parental varieties was based on the knowledge in fertility relations. The obtained sour cherry varieties represent the world-wide maximum quality, reliability and security of yields. Hungarian renewed sour cherry cultivation owes its fame and prosperity to those varieties, nevertheless also to the radical knowledge of the biological bases of fertility.
Apricot yields are highly variable according to the season. The variation is caused mainly by the adversities during the critical processes of floral biology, i.e. blooming and fertilisation. On the basis of information concerning blooming time and mutual compatibility relations of apricot varieties a system of securing regular and adequate yie...lds has been developed.
Winter frosts of the continental type are well tolerated by most of the apricots, however, after the end of rest period, flower buds are loosing frost tolerance, 'rapidly.
Being one of the fruit species blooming earliest during the early spring, apricot start to bloom in Hungary around the end of March or early April as a mean of many years, but it also happened, exceptionally that apricot started to bloom at February 20 (at Letenye South Hungary). The early season, exposes the floral organs to frost injuries. As a consequence, apricot orchards on the Great Plain produce low yields in 3 years, intermediate yields in other 3 years out of a ten-year-period.
Moreover, weather conditions during the blooming period are often unfavourable for pollination. Cool, windy and rainy weather prevents the flight of insects and on the other hand, warm spells shorten the blooming process, nectarines and stigmata get dry and the female gametes loose viability before effective pollination occurres.
The fertility of individual cultivars are meeting different obstacles. Apricot cultivars differ greatly in the rate of flowers bearing underdeveloped pistils, which may attain even 60% (e.g. Orangered). New commercial cultivars are often self-incompatible. Local varieties of that type in Hungary are the „óriás" varieties (e.g. Ceglédi óriás, Szegedi mammut), and the new hybrid Ceglédi Piroska. Many of the cultivars are variable in their self-fertility (partially self-fertile): Budapest, Harmat, Korai piros, Mandulakajszi.
Inter-incompatibility is also known in apricots. The „óriás " varieties do not fertilise each other. During the growth of fruits, cool spells (2-4 °C) caused severe fruit shed in Ceglédi óriás.
Apricot flowers produce pollen and nectar at average rates related to other fruit species, thus bees are attracted sufficiently. Bee visits are very variable according to growing site and season. Most of the bees are pollen gatherers but sometimes nectar suckers are in majority. Bee pollination is necessary not only for the self-incompatible varieties but also to enhance the yield of self-fertile varieties.
Taking the blooming and fertility relations of the cultivars into account, plantations should not exceed two rows to a particular self-incompatible varieties, and possibly two different polliniser varieties are suggested to be planted as flanking the block in question.
In commercial plantations 2 to 4 bee colonies per hectare are proposed to move for the whole blooming period.
The Apiaceae family consists of several species which are well known for their therapeutical use and also as spice plants. Although fennel (Foeniculum vulgare Mill.), caraway (Carton carvi L.), anise (Pimpinella anisum L.), coriander (Coriandrum sativum L.), dill (Anethum graveolens L.), angelica ...>(Angelica archangelica L.) and lovage (Levisticum officinale Koch.) are also economically considerable cultures, data on their flowering biology are rather scarce. This review supports data on the characteristic constitution of flowers and inflorescences, flowering dynamics, pollination mechanism and crossability of some of the most significant medicinal and spice species.
The inflorescence is a compound umbel. Flowers are hermaphrodite, however also monoeceous, mainly male flowers are turning up too. In blooming of a plant individual, a strict sequence is observed. The main umbel is the first to bloom, followed by the different range umbels in order of their range. In their pollination, both wind and insects are considered to be active. For each species, proterandry is characteristic. Although autogamy is considered to be almost unpossible, and geintonogamy as well as xenogamy to be the most characteristic ways of fertilization, several cases of self-fertilization proved to be also successful. Crossability among cultivars or species is depending on the genotype combination and usually produces less seed set than the above forms of fertiliiation.
The choice of varieties among medicinal plant species is relatively small, compared to other horticultural crops. In Hungary, only poppy (Papaver somniferum) and mustard (Sinapis alba) have several cultivars. Recognising the problem, in the recent years breeding activity has been intensified all over the world, in spite of fin...ancial, technical and legal difficulties. The article reports on the results of breeding at the Department of Medicinal and Aromatic Plants of the Szent István University, 11 varieties of which has been officially registered till 2000. Main goals of genetic improvement are: increasing of the production capacity of utilised plant organs, enhancement of active material accumulation capacity, improvement of sensory quality and technological properties. The most often applied methods are selection, and recently, cross breeding, the results of which can be measured on new materials of caraway (Carum carvi), hyssop (Hyssopus officinalis), marjoram (Majorana hortensis), poppy (Papaver somniferum), etc. Efficacy of breeding work is established by additional, regular research on the genetics, physiology, floral and reproductive biology, chemosyndromes of medicinal plant species.
The knowledge of blooming, pollination and fertilisation and its use are indispensable in maximizing of cropping potential of fruits in economical fruit production. In attaining maximum yield a greater attention has to be focused on choosing cultivar combinations, and results of experiments on blooming, pollination and fertilisation must be app...lied carefully.
To have efficient bee pollination requires attention at the time of designing an orchard. It requires further attention at the time of bloom of any of the fruit-hearing species. Markets demand new types of fruit which forces constant changes in the cultivar composition of orchard. The blooming, pollinating and fertilisation characteristics of cultivars chosen have to be known before an orchard is set up. Apart from the general knowledge of trees considered to be planted, there is a great need to know the flowering, pollinating and fertilization characteristics of each cultivar in detail.