Dormant vegetative structures, Biology

Assignment Help:

Dormant Vegetative Structures

You have learnt that light a period of chilling or application of gibberellin often breaks seed dormancy and stimulates seed germination. Vegetative organs such as tubers, corms, bulb and winter buds can also enter a period of dormancy. What kind of stimulus is required for these dormant structures to resume growth? It is observed that light can stimulate bud break in certain trees and a period of chilling is necessary for triggering the development of dormant buds, and other organs in plants of temperate region. The period of chilling required for the bud break is usually a week or more.

Similarly, lengthening of days is necessary for breaking dormancy of winter buds exposed to light. Dormant buds can also be stimulated by the application of gibberellins. As you know gibberellins promote growth and Abscisic acid inhibits the growth. Accordingly, on breaking of bud dormancy increase in the level of GA and fall in the level of Abscisic acid has been noted. It needs to emphasised here that though all the buds of a plant receive the same dormancy breaking stimulus, however, it is only the apical bud that grows and the growth of other buds is inhibited by it because of apical dominance. Plants reproduce vegetatively through rhizomes, runners or stolons. Tuber formation in potatoes can be induced by exposing leaves to day length less than the critical value. Artificial application of hormones show that in tuber formation gibberellic acid decreases while Abscisic acid increases. The results show that the level of a particular hormone can increase growth in some organ and decrease in other.


Related Discussions:- Dormant vegetative structures

Explain the criteria for assessment of vitamin status, Explain the Criteria...

Explain the Criteria for Assessment of Vitamin Status? Vitamin E is assessed by determining the plasma lipid fraction levels. 0.8 mg of total tocopherol/g total plasma lipids i

What is intrinsic rate of increase, In a population of e-coli, it turns int...

In a population of e-coli, it turns into 4 individuals in 1 day (assuming no deaths). What is it instantaneous per capita birth rate? Assume instantaneous death rate is 0.10. What

Define oseltamivir, Oseltamivir (Tamiflu)   This oral neuraminidase i...

Oseltamivir (Tamiflu)   This oral neuraminidase inhibitor, started within 36 hours of symptom onset, can decrease the severity and duration of symptoms caused by either influ

Gonads and ovary - reproduction, Normal 0 false false false...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Explain the sex composition of the population, Explain the Sex Composition ...

Explain the Sex Composition of the Population? Sex composition of human population is one of the basic demographic characteristics, which is extremely vital for any meaningful

Define thin layer chromatography, Define Thin Layer Chromatography? Thi...

Define Thin Layer Chromatography? This is an improvement over paper chromatography and uses thin layers of slurried absorbents like silica gel, alumina, cellulose, Kieselguhr,

Photosynthesis., what carbohydrates does a plant make from glucose

what carbohydrates does a plant make from glucose

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd