Breeding of Vegetable, Spice and Tuber Crops

Methods of pollination

• Vegetables may be grouped into four categories according to the way they pollinate
Group 1.

• Vegetables in Group 1 have flowers that can receive only their own pollen. They are called self-pollinizers.
Examples	Bush, pole and lima beans
	Chicory
	Endive
	English and Southern peas
	Tomatoes
Group 2.

• Vegetables in Group 2 form seed only with pollen from an unrelated plant.
Examples	cabbage
	radish
Group 3

• The cross-pollinated vegetables in Group 3 may either set seed from their own pollen (self-pollinated) or from pollen received from another plant (cross-pollinated). They can be divided into two sub-groups: (A) vegetables pollinated by air-borne pollen and (B) vegetables pollinated by insect-borne pollen.
Examples (A) usually pollinated by air-borne pollen:

Examples
Beets	corn
carrots	onions
celery	spinach
Swiss chard


Examples (B) usually pollinated by insect-borne pollen:

Examples
broccoli	kale	parsnip
Brussels sprouts	kholrabi	hot pepper
cauliflower	lettuce	sweet pepper
citron	muskmelon	pumpkins
collards	mustard	rutabaga
cucumbers	okra	squashes
eggplant	parsley	watermelons
gourds

Group 4

• Vegetables in Group 4 have both male and female plants. Seeds are formed only when male plants furnish pollen.
Examples	asparagus
	spinach
	some hybrid cucumbers


• Pollination may occur between vegetable cultivars, creating new cultivar varieties. For example, plants in the Cucurbitaceae or gourd family belong to four species among which crosses may occur. The success of such crossing depends on the species to which a variety belongs.


• Plants belonging to the Cucurbitaceae family produce separate male and female blooms on the same plant. Insects are usually required to cross-pollinate blooms. Pumpkins and squashes do not cross-pollinate with cucumbers, watermelons or citron. Watermelons and citron both belong to the genus Citullus and, therefore, will cross-pollinate each other. Muskmelons and Casaba melons will cross since they are both in the genus Cucumis and also in the same species, melo.