Breeding of Vegetable, Spice and Tuber crops (2+1)

Selection

Selection

Breeding in cardamom is currently based on selecting recombinants that are superior with regard to yield and quality of capsule and tolerance to biotic and abiotic stresses. Systematic evaluation of available germplasm followed by comparative yield trials and multilocational trials under various agro- ecological conditions have resulted in release of several improved selections in cardamom.

Selection for biotic and abiotic stress

Efforts are made to survey and collect disease escapes from hot spot areas of “Katte” disease and they were subjected to further evaluation by artificial inoculation. A natural Katte Escape (NKE) line was found promising and was released as IISR Vijetha for the mosaic infected areas of Karnataka and Wayanad in Kerala. A preliminary screening of cardamom varieties for “azhukkal” disease showed that Malabar and Vazhukka were more susceptible compared to Mysore. Survey, collection and evaluation of drought escapes from low rainfall areas are also been done to select a drought tolerant type.

Hybridization

Intervarietal hybridization using genetically divergent genotypes started as early as 1976. Cardamom hybrids being heterozygous and heterogenous in nature have to be multiplied either clonally or through micropropagation to produce “true to type” planting materials and to avoid segregation.

Polycross breeding

Being a cross pollinated crop, polycross method of breeding may be useful to get better varieties. Elite clones having predominantly desirable characters are inter- planted in an isolated plot. Two to three beehives can also be maintained in the plot for assured pollination so that maximum fruit set as well as high number of seeds per capsule could be obtained. Since parents have superior characters their progeny might possess a combination of desirable characters. Cardamom yield could be substantially improved through a poly cross breeding programme. Up to 60% increase in yield was obtained from a polycross progeny of Mudigere-1. A population of more than 3000 plants is essential for carrying out effective selection.

Mutation and polyploidy breeding

The objective of mutation breeding is to develop clones tolerant to cardamom mosaic (Katte) virus and drought. Induced mutants (through x-rays, gamma rays, EMS and MH) were developed in cardamom but none was derivable. Polyploids (2n= 4x = 96) were also successfully induced in cardamom, but they were inferior to diploids.