Question

Example of recalcitrant seeds are
A. Cereals and legumes
B. Mango, cocoa, and rubber
C. Cereals and tropical fruits
D. All of the above

Answer 1

Hint: Recalcitrant seeds are called unorthodox seeds and they are short-lived, and not able to tolerate low temperature and moisture, less than 10$^{\circ}$C and 20-30 percent moisture respectively, if they go below such conditions then they are losing their viability.

Complete answer:
Seeds that are produced by plants are categorized into two groups such as orthodox seed and unorthodox seed (Recalcitrant seed).
1. Orthodox seeds: These types of seeds are long-lived seeds and easily dry their moisture content as much as 5 percent and they can easily tolerate low temperature for storing purposes, without losing their viability. Such kinds of seeds are also called desiccation-tolerant seeds. Orthodox seed belongs to mostly biennial crops, annual and agroforestry species. Example of orthodox seeds is cashew, guava, mostly grains, and legumes. The viability of such orthodox seeds range from one year to hundreds of year that depends on species and storage condition
2. Recalcitrant seeds: Such seeds are also known as unorthodox seeds, they are short-lived and not able to tolerate low temperature and moisture if they face any such condition so they will lose their viability. They are difficult to store in ex-situ conditions. Such seed belongs to those shrubs and trees which grow mostly in temperature or tropic regions, examples:- cacao, avocado, coconut, jackfruit, mango, tea, rubber, jackfruit, and some horticultural trees.
3. Intermediate seeds: such seed possess moderately desiccation-tolerant but sensitive to low temperature. Coffee and citrus seed belongs to this seed group.
Hence, the correct option is (B).

Note: Seed are the ripened ovule, seeds are of two types on the bases of its cotyledon, such as monocot which possess only single cotyledons while in dicot seed bear two cotyledons. Both are found in different plant groups such as monocot and dicot plants.