Potato and Tuber Crops

Breeder Seed Production Technology at CPRI

Breeder Seed Production Technology at Central Potato Research Institute (CPRI)

1. Single Plant Selection
• Only healthy plants are singled out and only those single plants having good yield, true to type (in shape) and with uniform sized tubers, are selected.
• Approximately 75-80 single plants are selected to feed one hectare of breeders seed plot in I-IV stages multiplication system.
2. Tuber Indexing
• From an individual plant produce, usually four large sized tubers are selected for indexing.
• One single eye from each of such numbered tubers from crown end is excised with the help of a scooper.
• If these are dormant, then the eyes are treated with GA3/ thiourea and planted in a glass house.
• These plantlets are tested for PVX, S, Y, A and leaf roll, either by ELISA or conventional serological/biological/histochemical tests.
• On the basis of the result of this indexing, the tubers are declared healthy or unhealthy.
3. Multiplication of Healthy Indexed Tubers

Stage I

• All the healthy indexed tubers are multiplied in field at a wider spacing of 1 x 1 m in hills or 1.2 x 1 m in plains.
• The growing crop in addition to three visual inspections for rouging is also tested cent per cent either by ELISA or by simple sap agglutination test on the slides.
• All cultural and plant protection operations are followed well in time.
• Finally, the diseased-free hills are harvested and stored as individual clones/hills.

Stage II

• The produce of each clone is planted in separate rows at wider inter row spacing of 1 or 1.2 m and intra-row spacing of 20 to 40 cm as per the size of tubers.
• Besides visual roguings, all clones are 100 percent tested serologically in groups of 4-5 plants each.
• All the cultural practices are followed as in stage I.
• The healthy clones are bulk harvested

Stage III

• The bulk produce of stage II is multiplied in next season at normal spacing of 60 x 20 cm.
• Three visual inspections for rouging and 300 plants/ha are check tested for PVS and X serologically to assess the health standard of the crop.
• All precautions and cultural practices are strictly followed to raise a healthy crop.

Stage IV

• Large scale multiplication of stage III produce is carried next year for production of breeders seed.
• The serological check testing is of 100 plants/ha to assess the health standard.
• Finally, the breeders’ seed crop is monitored by the monitoring team and the breeders seed inspection certificate is accorded on satisfaction of the crop being of desired health standard (Tunwar and Singh, 1988).