How do you classify the corn?
Time：2017/7/20 19:17:59 Clicks：1427
During the long-term cultivation of maize, a large family system has been formed due to the Directional Cultivation of human beings and the variation of adaptation to environment. In classification, maize belongs to the family Gramineae, maize, and corn. According to the botanical and biological characteristics of maize, maize can be classified as follows.
1. according to the grain morphology and structure classification
Durum ear is conical, grain hard, rounded at the top, there is grain at the top and around the luster, the endosperm is horny endosperm, endosperm is only a small part of the center of powder endosperm. The grain is mostly yellow, followed by white, red and purple. The durum varieties have the characteristics of good quality, early maturity, low yield, stability and adaptability. Durum corn is mostly landrace.
Dent ear for the cylindrical grain, large flat square or long flat grain, on both sides of middle and top horny endosperm endosperm is silty, mature grain at the top of the depression was dentate. The grain color is yellow, the second color is white, the red purple. The quality of dent is low and yield potential is big, which is the main type of cultivated varieties.
Semi dent hybrids derived from flint and dent type, ear length conical or cylindrical, between grain and starch between flint and dent. Better quality, higher yield, more varieties used in production.
Waxy type or waxy type. The endosperm is composed of horny starch, opaque and dull, waxy, waxy, and red. There are two kinds of color: yellow and white. Waxy type is a new type of maize introduced into China, and its cultivation area is not large.
Sweet type also called sweet corn, because the recessive genes of different kinds, is divided into ordinary sweet corn and super sweet corn two. The endosperm of grain mostly consisted of keratin starch, and the content of sugar in the milk stage was 12~18%. When mature, the sugar was not converted into starch in time, and the kernel shriveled after drying. Yellow, white and so on. Generally used for edible and processing can tender ear.
Silty grain and hard corn endosperm similar by silty starch composition, only a small amount of outer horny starch, soft, easy grinding. Low yield, poor storage and susceptible to weevils.
Sweet powder grain is horny endosperm, sugar containing starch, lower powder endosperm, the production value of small.
Burst type small spike axis fine grain, grain hardness, grain shape and a prominent top, pearl shaped two shapes, for a small amount of horny endosperm, silty central starch. The grains are mostly yellow and white, with less red and purple. Used mainly for popcorn and pastries.
Pod type plant leaf, grain pod wrap, sometimes awn, often sterile, hard grains, with various shapes and colors, threshing inconvenience, no cultivation value.
2. according to morphological classification
According to plant height divided into high stalk type (plants more than 2.5 meters), culm type (plant height of 2 meters ~2.5 meters) and dwarf type (height 2 meters).
According to the 3. leafexpanding angle classification
According to leaf expansion of the different point of view, can be divided into flat type maize and compact plant type varieties. The flat type of plant shape should be tall and thin planting; compact compact plant type, unit area can be intercepted more light, the potential yield significantly, is a main type of high yield maize hybrids at present, such as Yedan series of high yield varieties.
4. classification according to the growth stage
Early spring growth period of 70~100 days, 10 DEG C temperature of 2000 DEG ~2200 DEG, short stalk, fine, 14 pieces of ~17 leaf, ear to the short conical, small grain, grain weight 0.15 kg ~0.25 kg, summer growth period of 70 days ~85 days.
~120 100 days to mature spring growth period days, temperature is about 2300 degrees Celsius ~2600 degrees Celsius, 18 pieces of ~20 in ear leaf, medium size, weight 0.2 kg ~0.3 kg. The summer sowing period is 85 days and ~95 days.
~150 120 days late spring growth period for more than 2600 days, the accumulated temperature of ~2800 DEG C, the plant is tall, 22 pieces of ~25 leaf, ear weight larger, about 0.3 kilograms. The growth period of summer sowing is more than 96 days.
5. according to use and grain composition classification
According to the composition of grain and special purpose, can be divided into special maize and common maize two categories.
Refers to special corn has high economic value and nutritional value of processing and utilization of corn or maize, these types of features, which have their own purposes, special processing requirements. Special corn outside the corn types namely common maize. Generally refers to the special maize high lysine corn, waxy corn, sweet corn, popcorn, high oil corn.
(1): sweet corn also called fruit corn, can be eaten directly after cooking, but also can be made into various flavors of canned and processed foods and frozen foods. Sweet corn is sweet because of the high sugar content of corn. The sugar content in the kernel varied with different periods, and the sucrose content was 2~10 times that of the common corn during the optimum harvest time. Because of genetic factors, sweet corn can be divided into 3 categories: general sweet corn, strengthening sweet corn and super sweet corn. Sweet corn is selling well in developed countries.
(2): also known as sticky glutinous maize corn endosperm starch composed almost entirely of amylopectin. The difference between amylopectin and amylose is that the molecular weight of the former is much smaller than that of the latter, and the digestibility of the food is higher than 20%.