Essential Conditions for germination of a seed

Transcript

Example 1 - Germination Germination of Kidney bean Example 2 - Germination Germination of Pea Seed Example 3 - Germination Germination of Corn Seed What is Germination? Germination is the process by which a seed starts growing into a new plant under suitable conditions. Germination of Kidney bean Germination of Pea Seed Germination of Corn Seed What are Essential Conditions for germination of a seed ? Seeds require water for germination. Water enables the seeds to carry out the processes necessary for their growth. The outer covering of the seed is called seed coat. Water softens the seed coat and helps the tiny embryo inside it to develop into a plant. Air and Soil: Seeds need both air and soil for germination. They use the air available in the spaces between soil particles. Moreover, spaces between the soil particles allow roots to grow easily. Sunlight: In general, most seeds do not require sunlight for germination. But after germination, sunlight is required for further growth of the seedling. Activity 10.2Take four identical pots filled with garden soil. Sow four bean seeds in each pot. Now, keep these pots in the conditions given in Fig 10.1 for 15 days. (a) Pot kept in (b) Pot kept in (c) Pot with (d) Pot with moist direct sunlight, no direct sunlight, moist soil, kept soil, kept in direct water excess water in the dark sunlight Fig 10.1: Bean seeds exposed to different conditionsIndicate the availability of air, sunlight and water for the seeds in each of these cases in Table 10.2. When a seed turns into a sprout, it is said to have germinated. Predict whether the seeds in each pot will germinate. Record your predictions for each pot kept under different conditions in Table 10.2 Regularly observe the pots for 7–10 days to check the status of germination of the seeds. Record your observations in Table 10.2. Compare your predictions with your observations. Table 10.2Table 10.2: Effect of certain conditions on seed germination Pot with bean seeds Availability of Seed germination Possible reason for the observation Air Sunlight Water Prediction Observation A: In direct sunlight and without water Yes Yes No Seeds will not germinate Seeds do not germinate Water is necessary for germination B: In direct sunlight and excess water Very Little Yes Too Much Seeds will germinate Seeds do not germinate Excess water removes air from soil C: In complete dark and moist soil Yes No Yes Seeds will germinate Seeds germinate Sunlight is not needed for germination D: In direct sunlight and moist soil Yes Yes Yes Seeds will germinate Seeds germinate All conditions required for germination are present