Principles of Plant Breeding (2+1)

Characteristics of asexual crops

• Majority of these are perennials like sugarcane and fruit trees. The annual crops are mostly tuber crops e.g. potato and sweet potato.
• These are highly heterozygous indicating the evolutionary advantage of heterozygote in these crops which leads to high degree of inbreeding depression on account of increased homozygosity on selfing.
• Many of these crops are interspecific hybrids and are polyploids.
• These are highly cross pollinated.
• Most of these crops show reduced flowering and certain varieties do not even flower at all. The seed set through normal sexual reproduction is usually low.
• On account of their heterozygous nature the first generation of varietal crosses displays enormous variation and appearance of un-adapted and weak recessives in the progeny.