In micropropagation of lily, preferably bulblets should be produced: Because bulblets are compact and robust, they are much easier to handle and to plant in soil than shoots. In this review, the various factors that determine bulblet... more
In micropropagation of lily, preferably bulblets should be produced: Because bulblets are compact and robust, they are much easier to handle and to plant in soil than shoots. In this review, the various factors that determine bulblet growth in vitro are discussed. Gibberellins, jasmonates (JA) and abscisic acid (ABA) are the major identified plant growth regulators (PGRs) for storage organ formation. They also play a major role in lily bulblet growth in vitro. Growth conditions such as temperature and light (quantity and quality) strongly affect lily bulblet growth in tissue culture. Moderate abiotic stresses are introduced as new tool to improve storage organ formation in vitro. The amounts of endogenous carbohydrates (starch) in the explant and exogenous carbohydrates in the medium (sucrose) influence bulblet growth in vitro. It is also discussed how compounds present in the medium or in the scale-explants are translocated to the regenerating bulblet.
Research Interests:
Micropropagated Lilium speciosum Thunb. bulblets were cold-treated at 2C for various periods before being planted in soil. About 20% of uoncold-treated bulblets and 100% of bulblets cold-treated for 6 weeks sprouted within 10 weeks after... more
Micropropagated Lilium speciosum Thunb. bulblets were cold-treated at 2C for various periods before being planted in soil. About 20% of uoncold-treated bulblets and 100% of bulblets cold-treated for 6 weeks sprouted within 10 weeks after planting. Intermediate lengths of cold treatment resulted in intermediate percentages of emergence. The remaining 80% of the noncold-treated bulblets sprouted synchronously from 25 to 33 weeks after planting. In these bulblets, the number of scales increased before sprouting. A sample of bulblets that had received a short cold treatment (2 or 3 weeks) also showed biphasic emergence, with the second period between 25 and 33 weeks. When the cold treatment was interrupted by 3 weeks at 17C, the percentage of emergence during the first period was reduced and the timing of the second period advanced.
Research Interests:
Ornamental geophytes comprise a large and diverse group of plants characterized by underground storage organs that serve the obvious function of reserve storage and subsequent supply during early stages of shoot growth. Relative to many... more
Ornamental geophytes comprise a large and diverse group of plants characterized by underground storage organs that serve the obvious function of reserve storage and subsequent supply during early stages of shoot growth. Relative to many agronomic and horticultural crops, the fundamental physiological bases of carbon metabolism, partitioning, and utilization in geophytes are unclear. One reason is diversity in organ morphology (bulb, corm, tuber, root, rhizome, etc.), storage carbohydrate (starch, fructan, glucomannan, etc.), and growth habit (e.g., synanthous vs. hysteranthous flowering). Knowledge of factors that control accumulation and mobilization of carbohydrate reserves may lead to manipulations that considerably improve the quality and culture of these crops. We are utilizing a variety of techniques and experimental systems to study selected internal and external controls or influences on geophyte carbohydrate metabolism and partitioning. Specific examples to be discussed inc...
Research Interests:
The major fraction of seed storage proteins of Agrostemma githago (corn-cockle), a non-leguminous dicot, occurs as material with S20,w values of approximately 11S and approximately 2S, and a minor fraction as oligomers with S20,w values... more
The major fraction of seed storage proteins of Agrostemma githago (corn-cockle), a non-leguminous dicot, occurs as material with S20,w values of approximately 11S and approximately 2S, and a minor fraction as oligomers with S20,w values of approximately 6.5S. The 11S proteins are of the legumin type and consist of disulphide-linked α- and β-subunits of Mr approximately 39 000 and approximately 23 000 respectively. The oligomeric assembly of the precursor polypeptides of the 11S proteins was examined. The approximately 65 000-Mr precursor polypeptides of two 11S proteins, which consist of 38 000-25 000-Mr subunits and 36 000-22 000-Mr subunits respectively, were assembled into oligomers of approximately 7S and subsequently cleaved. Thereafter the 11S oligomer was formed. The 88 000-Mr precursor of a third 11S protein, which consists of 41 000-23 000-Mr subunits, was assembled into an approximately 8S oligomer and then cleaved, yielding two disulphide-linked intermediates of Mr 59 000...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
De veredeling van tulp gaat traag door de lange generatietijd en door langzame vermeerdering op het veld. Een veredelingsprogramma van tulp duurt al snel 25 jaar. Dit kan aanzienlijk verkort worden door vermeerdering in weefselkweek. Er... more
De veredeling van tulp gaat traag door de lange generatietijd en door langzame vermeerdering op het veld. Een veredelingsprogramma van tulp duurt al snel 25 jaar. Dit kan aanzienlijk verkort worden door vermeerdering in weefselkweek. Er is nu een werkbaar protocol
Research Interests: Computer Science and Art
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Botany, Horticulture, Plant Biology, Biology, Abiotic Stress, and 4 morePlant Physiology, In Vitro, Rhizome, and Shoot
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Lilies regenerating on scale segments may develop dormancy in vitro depending on the culture conditions. The dormancy is broken by storage for several weeks at a low temperature (5 °C). The effect of the low temperature on sprouting, time... more
Lilies regenerating on scale segments may develop dormancy in vitro depending on the culture conditions. The dormancy is broken by storage for several weeks at a low temperature (5 °C). The effect of the low temperature on sprouting, time of leaf emergence and further bulb growth was studied. Dormant and non-dormant bulblets were regenerated in vitro on bulb scale segments
Research Interests:
Research Interests:
Research Interests:
Lily bulblets produced in tissue culture at 20 or 25ºC are cold-treated before planting to break dormancy. Bulblets produced in tissue culture at a relatively low temperature (15ºC), though, are nondormant and sprout without a preceding... more
Lily bulblets produced in tissue culture at 20 or 25ºC are cold-treated before planting to break dormancy. Bulblets produced in tissue culture at a relatively low temperature (15ºC), though, are nondormant and sprout without a preceding cold treatment. Leaves generated after planting by noncold-treated 15ºC bulblets, were relatively small and as a consequence bulblet growth after planting was limited. This
Research Interests:
Alstroemeria rhizomes were micropropagated on semi-solid medium (AM) and in liquid medium (LM). In LM, growth was much enhanced (ca. 70%). Adequate gas exchange was crucial. This was obtained by agitation and in static medium by a... more
Alstroemeria rhizomes were micropropagated on semi-solid medium (AM) and in liquid medium (LM). In LM, growth was much enhanced (ca. 70%). Adequate gas exchange was crucial. This was obtained by agitation and in static medium by a sufficient large contact area of the explant and the gaseous atmosphere of the headspace. The medium became rapidly depleted with respect to both
Research Interests:
Research Interests:
Research Interests:
Hyperhydricity (also known as ‘vitrification’) is a physiological disorder in tissue-cultured plant material, which causes a reduction of propagation and death of tissues when transferred to ex vitro conditions. A plethora of causes has... more
Hyperhydricity (also known as ‘vitrification’) is a physiological disorder in tissue-cultured plant material, which causes a reduction of propagation and death of tissues when transferred to ex vitro conditions. A plethora of causes has been mentioned in literature. We consider this disorder as the result of the stressful conditions brought about by waterlogging of the apoplast. This causes hypoxia and
Research Interests:
Research Interests:
... and colonized and the ancient philosophies of platonism, stoicism and atomism were being ... At the same time, biological theories became influenced by the advance of chemistry. ... a cellfree yeast extract converted glucose into... more
... and colonized and the ancient philosophies of platonism, stoicism and atomism were being ... At the same time, biological theories became influenced by the advance of chemistry. ... a cellfree yeast extract converted glucose into alcohok Furthermore, the cell theory, by positing that ...