Genetics and wild type genes

Plants are able to response on influences caused by several biotic or abiotic stress factors. These responses are described under the heading “general adaptation syndrome” (LARCHER 1994, SCHLEE 1992). The following reactions take place within the framework of this syndrome: The stressor trigger a state of alarm in the organism and this initially leads to a reduction in vitality (phase I). After a short restitution phase, there then follows a phase of resistance (phase II) which comprises not only resistance responses but also tolerance responses, including increased productivity on the part of the plant, with the aim of adapting to the stressor. Only if adaptation fails does the plant enter the exhaustion phase (phase III), which is associated with irreversible damage. This means: The vitality and survival capability of plants under stress can be influenced in two different ways: Resistance (=ward off the stressor) and tolerance (=reduce the damage caused by the stressor). The most crop plants were bred or selected for resistance and/or high yields. Thus the ability of tolerance of crop plants was tolerance ignored and diminished. They lost the ability to tolerate stresses. Wild plants have kept their ability of tolerance. That why wild plants can overcome biotic and abiotic stresses better than crop plants.

Hi Waqas,

We know that wild plants are as a gene pool and they are using for breeding objectives of cultivated plants. Because of evolution in many years (decades/centuries) they are adapted for different climates and conditions. During adaptation, they faced with variety of conditions (such as light, temperature, soil, water, etc.) that caused morphological and genetically (DNA methylation, mutation, etc.) differences. In the other words, stress-resistant genes of domesticated plants are decreased because of domestication process (ideal growth conditions). So, wild plants are more tolerant than the cultivated plants.

Dear Ali, dear Waqas, a supplement: We have to consider various levels of plant responses to stress. The molecular level, the cellular, the organelle, the tissue network and organ systems and at last but not least the whole plant as a single individual. Genes may be the molecular reason for responses but they are not the single respond. Always the plant will respond as a whole, as individual to stresses. And these responses of resistance and/or tolerance are described by the general adaptation syndrome (see above). Other import points of adaptation to stresses are the responses of population of a kind of plants, therefore many single individuals, key word physiological plasticity...

Dear Petra Seidel

Thank you very much. I would like to know what are the reasons for adaptation and how to develop it

Dear Petra,

very nice question, and very good answers given by different colleagues. Effectively, it seems that crop plants have been selected for the higher yield (in term of production), ensuring the best environment by cultural practices. Wild plants must survive, growth and reproduce under conditions of envrionental constrains and very high level of interspecific competence...with no help from cultural practices that can reduce both.

In fact, the Grime´s theory of plant startegies can help you to understand in a deeper way these relationships.