Detailed Explanation of Key Points of Pollination Technology for Hybrid Seed Production of Pepper

The key to the seed production of pepper F1 hybrids is the purity and yield of hybrid seeds, and the factors affecting purity and yield include the purity of parent seeds, cultivation management, isolation and pollination technology, among which pollination technology is particularly important. Now let us discuss the process and methods of pollination.

1. Preparations before pollination

1.1 Making of the pollination tube and the marking-ink pen

The pollination tube is a hollow glass tube with an opening at the top of one end and a small hole on the side of the other end. The tube is 6 cm long, with an outer diameter of 4 mm and an inner diameter of 3 mm; the small hole has a diameter of 1.5 mm. When making the tube, the edge of the small hole must be made sufficiently smooth.

Method for making the marking-ink pen: remove the refill of a painting watercolor pen, pour marking ink into the pen barrel, and it is ready for use. The marking ink formula is 75%-85% letterpress printing ink (red) plus 15%-25% paint (varnish or red paint), then add an appropriate amount of edible oil (such as rapeseed oil, cottonseed oil, peanut oil and other vegetable oils) to adjust the consistency.

1.2 Field inspection and plant adjustment

Check the purity of the male and female parents, and remove off-types and inferior plants. The flowers and fruits at the first node of the male and female parent plants should be thinned out. All opened flowers and all fruits on the female parent plants should be removed, and it is best to also prune off the weak, thin branches below the first pepper.

2. Pollen collection and hybrid pollination

2.1 Pollen collection

Every day from 6:00 to 8:00 in the morning (can be appropriately postponed when the temperature is low or on cloudy and rainy days), pick flower buds about to open on the male parent plants (the corolla is fully whitish, with the tip slightly split) or flowers that have just opened but whose anthers have not yet split, immediately take out the anthers with tweezers, place them in a container, and dry them in a dry place with weak light, then sift the pollen with a 60-100 mesh pollen sieve, put it into the pollination tube, and plug the tube opening tightly with a rubber stopper for later use. In production, it is best to use fresh pollen of the same day, and to use little or no pollen from the previous day.

2.2 Pollination time, node position and bud age

The pollination period differs slightly among different regions. In the Hefei area, early May to mid-June is relatively suitable.

The daily pollination time varies slightly with changes in temperature and air humidity. When the temperature is lower and the air humidity is higher, flowering is delayed, so pollination should be postponed accordingly; otherwise, pollination should be advanced. Generally, 7:00-10:00 in the morning is suitable, among which 8:00-9:00 is the best, because during this period the stigma secretes more exudate; in the afternoon, after 3:00 is suitable. If the temperature is suitable, pollination can be carried out all day.

The best node positions for pollination are the 2nd to 5th nodes. If the flower at the 1st node is retained for pollination and seed production, it will affect the vegetative growth of the plant; fruits above the 5th node have light seeds and poor quality.

The criteria for judging the best bud age for pollination are: the flower bud has fully expanded, the bud has turned white, and it splits open with a gentle pinch of the hand. For such flower buds, the style has matured and the anthers have not split. If the flower bud is small (greenish-white), it is not easy to set fruit, and the seed yield is also low.

2.3 Operation process and precautions of pollination

Fix the pollination tube to the middle-front part of the marking-ink pen with a rubber band, with the end having the small hole close to the pen tip. Pen-holding posture: use the index finger and middle finger of the right hand to clamp the front part of the pen shaft, with the rear end of the pen shaft between the thumb and index finger, and note that the small hole of the pollination tube should face upward. When pollinating, pinch the junction of the flower stalk and the receptacle with the left hand and keep it still, gently pinch the part of the corolla close to the receptacle with the thumb and index finger of the right hand, and twist slowly; the corolla and anthers will then be removed (the anthers are connected with the corolla), exposing the style and ovary. Then extend the style vertically into the small hole of the pollination tube, dip it with saturated pollen, and then make a mark by applying a stroke on the flower stalk with the marking-ink pen.

During pollination, when searching for flower buds that can be pollinated, do not push leaves aside with your hands; you may lift several leaves on the upper part of the plant with your hand and gently part them, because pepper branches and leaves are relatively brittle and easy to break. In addition, when twisting off the corolla, do not injure or break the style (the style is very delicate); after pollination, do not let the style contact the leaves. During use, the pollen tube should be frequently held upright so that the pollen remains in a state of filling the bottom of the tube.

During pollination, remove any flowers that have already opened, and promptly pull out diseased plants. After the pollination period ends, promptly remove the whitish flower buds; generally, after 3 successive layers of flowers are set, top the plants. At the same time, strengthen fertilizer and water management, and control diseases and pests, etc.