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

Breeding methods

• The breeding methods used for improvement of cucumber are introduction, selection, hybridization and heterosis breeding.

Introduction

• Varietal improvement programme in India started with introduction of varieties from foreign countries and these were recommended for commercial cultivation. These include Japanese Long Green, Straight Eight and Poinsette.

Selection

• Some varieties such as Sheetal, Khira 90 and Khira 75 were developed by employing selection procedure and released.

Hybridization

• Two varieties, Himangi (Poinsette x Kalyanpur Ageti) and Phule Shubhangi (Poinsette x Kalyanpur Ageti) were developed by hybridization followed by selection.

Heterosis breeding

• Heterosis breeding has brought about much improvement in cucumber.
• The open pollinated cultivars of cucumber are monoecious in sex form.
• A few attempts have been made to exploit monoecy in heterosis breeding in this crop. Examples are: Poona Khira x Japanese Long Green, Chaubatia Local x Solan Local, White Long Cucumber x Poinsette and Kalyanpur Ageti x Panvel. However, more of these hybrids are commercially exploited or grown by farmers.
• Presence of gynoecious sex forms has made possible phenomenal progress in exploitation of F1 hybrid under glass house conditions. The first F1 hybrid, Pusa Sanyog developed in India in 1971 has a gynoecious female parent.
• It is suited to subtropical and cooler conditions also. This hybrid has shown heterosis for early yield, total yield and number of fruits per plant.

Resistance breeding

• The Indian variety Banglora was the starting point for developing downy mildew resistance in cultivars in the United States. The cucumber cultivars, All Season, Improved Long Green and Korea Dutch are less susceptible to red pumpkin beetle.
• Moderate resistance to Meloidogyne incognita has been observed in line GY 59 37-587.