OPTIMIZATION OF WEED SEED DORMANCY BY CHEMICAL AND PHYSICAL TREATMENTS | PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

A very significant ecological role is played by weed dormancy. It prevents the seeds from germinating as soon as possible and from being killed by unfavorable climatic conditions for their development. Dormancy is the outcome of a complex relationship between the genome and the agroclimatic factors encountered during their "reproductive and vegetative phase" by seed-bearing plants. Awareness of the time of emergence and the dynamics of the germination of weed seeds and the factors that affect them gives us an idea of the infestation of these weeds in agricultural areas, which would decrease the use of herbicides without affecting crop yields or the level of weed control. The results of seed germination tests and the emergence of dormancy of the following weeds are described in this paper: Phalaris brachystachys, Avena sterilis, Ridolfia segetum, Centaurea diluta, Cichorium endivia, Lolium rigidumn and Picris echioides, in which four methods were applied to seeds, a chemical treatment with the phytohormone giberelic acid (GA3), mechanica mechanica, in order to encourage germination. The results showed that mechanical and chemical scarification, with an average of 81.42 percent and 75.23 percent respectively, reported the highest germination percentages in our genus, whereas stratification (0 ° and 4 °) gave a low average of 62 percent and 67 percent . The findings found confirm with others that mechanical scarification and chemical treatment with gibberellic acid induces to a greater degree germination of the seeds examined. A physical dormancy caused by their teguments is thus exposed. This will allow farmers to use 0° and 4° stratification to block germination of seed weeds.

Please see the link :- https://www.ikprress.org/index.php/PCBMB/article/view/5534

METAL STRESS ON SEED GERMINATION AND GROWTH | PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

 Heavy metals are non-biodegradable which form the major group of environmental pollutants and can harm humans and other living organisms via food chains, often leading to toxicosis, thus are bringing attention towards themselves for studies and research. The heavy metals which can cause toxic effects to plants; leading to less productivity and effecting the agro-ecosystem; include lead, cadmium, copper, cobalt, nickel etc. The metal toxicity in plants manifest through an array of physiological and metabolic alterations which may include alteration in key enzyme activities, protein mobilization, photosynthesis and synthesis of metal detoxifying compounds due to induction of oxidative stress. There is an increase in the generation of reactive oxygen species on accumulation of metal ions in plant tissues which can be decreased with the help of antioxidants due to its ability to trap free radicals. Also in some plants metals as trace elements are essential for normal metabolic function but are toxic in higher concentrations thereby are hampering the physiological and metabolic functions of plants. Further, it has been observed that due to metal stress some plants produce heat shock proteins and which can affect the photosynthesis by destabilizing enzymes. This review is summarized to understand the effect of metal stress on seed germination and growth.

Please see the link :- https://www.ikprress.org/index.php/PCBMB/article/view/5216