Detailed Explanation of Key Points for Scientific Seed Saving of Spinach
Spinach is an annual or biennial herb of the genus Spinacia in the subfamily Chenopodioideae of the family Amaranthaceae. Also known as boleng and Persian herb. Its leaves and tender stems are eaten. Spinach originated in Persia and was already cultivated 2000 years ago. It later spread to North Africa and was introduced by the Moors to Western European countries such as Spain. Spinach was introduced to the Tang Dynasty in 647. Spinach has a well-developed main root; the fleshy root is red and sweet-tasting and edible.
Morphological Characteristics of Spinach
Spinach can reach up to 1 m in height and is not powdery. The root is conical, reddish, rarely white. The stem is erect, hollow, brittle and juicy, unbranched or with a few branches. The leaves are hastate to ovate, bright green, tender and juicy, slightly glossy, entire or with a few tooth-like lobes. The male flowers are grouped into spherical glomerules, which are further arranged on the upper parts of the branches and stem into an interrupted spicate panicle; the tepals are usually 4, the filaments are filiform and flattened, and the anthers have no appendages; the female flowers are clustered in the leaf axils; the bracteoles are slightly flattened on both sides, with 2 small teeth remaining at the apex and usually 1 spine-like appendage on the back of each; the ovary is spherical, and the stigmas are 4 or 5 and protruding. The utricle is ovate or nearly circular, about 2.5 mm in diameter, flattened on both sides; the pericarp is brown.
Nutritional Components of Spinach: Spinach is known as the “model student of nutrition.” It is rich in carotenoids, vitamin C, vitamin K, minerals (calcium, iron, etc.), coenzyme Q10 and many other nutrients.
Main Functions and Indications of Spinach: Nourishes the blood, stops bleeding, preserves yin, and moistens dryness. Treats epistaxis, hematochezia, scurvy, excessive thirst with profuse drinking, and dry and sluggish bowel movements.
Scientific Seed Saving Techniques for Spinach
The sex types of spinach plants can be roughly divided into the following four kinds: first, the absolute male plant, which bears only male flowers. Second, the vegetative male plant, which bears only male flowers and, compared with the absolute male plant, has larger basal leaves and bolts later. Third, the female plant, which bears only female flowers and bolts later than male plants. Fourth, the monoecious plant, on which the same plant bears female flowers and male flowers, or bears “bisexual flowers,” and whose flowering period is close to that of female plants.
When some plants in the seed-saving field are found to have begun bolting, the absolute male plants, early-bolting female plants, as well as diseased plants, weak plants, hybrid plants, etc., should be promptly removed, and a topdressing should be applied immediately afterward to encourage the seed plants to produce more branches. After that, part of the vegetative male plants should also be removed successively. Usually, for every square meter, only 3-5 vegetative male plants that flower at the same time as the female plants need to be left (for pollination). After the female plants set seed, all vegetative male plants can be removed to promote the development and maturation of the seeds.
When most of the stems and leaves of the plants have withered and turned yellow and the pericarp has turned yellow-green, the seed plants can be harvested. After being piled for 3-5 days to undergo “after-ripening,” they are then threshed, dried and stored.
For the production of hybrid spinach seeds, a planting pattern of 1:4 rows of the paternal and maternal parents is generally advisable, but attention must be paid to continuously and thoroughly removing all male plants and bisexual plants in the maternal rows, as well as all female plants and bisexual plants in the paternal rows, in a timely manner. Because the sex types of spinach plants are relatively complex, attention should be paid to mastering the seed-saving techniques well.
The sex types of spinach plants can be roughly divided into the following four kinds: first, the absolute male plant, which bears only male flowers. Second, the vegetative male plant, which bears only male flowers and, compared with the absolute male plant, has larger basal leaves and bolts later. Third, the female plant, which bears only female flowers and bolts later than male plants. Fourth, the monoecious plant, on which the same plant bears female flowers and male flowers, or bears “bisexual flowers,” and whose flowering period is close to that of female plants.
When some plants in the seed-saving field are found to have begun bolting, the absolute male plants, early-bolting female plants, as well as diseased plants, weak plants, hybrid plants, etc., should be promptly removed, and a topdressing should be applied immediately afterward to encourage the seed plants to produce more branches. After that, part of the vegetative male plants should also be removed successively. Usually, for every square meter, only 3-5 vegetative male plants that flower at the same time as the female plants need to be left (for pollination). After the female plants set seed, all vegetative male plants can be removed to promote the development and maturation of the seeds.
When most of the stems and leaves of the plants have withered and turned yellow and the pericarp has turned yellow-green, the seed plants can be harvested. After being piled for 3-5 days to undergo “after-ripening,” they are then threshed, dried and stored.
For the production of hybrid spinach seeds, a planting pattern of 1:4 rows of the paternal and maternal parents is generally advisable, but attention must be paid to continuously and thoroughly removing all male plants and bisexual plants in the maternal rows, as well as all female plants and bisexual plants in the paternal rows, in a timely manner.