Maize is one of the most widely distributed food crops in the world, and the area planted is second only to wheat and rice. In China, maize is grown in most areas and is one of the main foodstuffs for people in the north and southwest regions. Laixi City, Shandong Province is one of the important corn producing areas. The quality of corn in Kailu County is very high. Corn can be divided into different types according to different methods. For example, according to color, it can be divided into white corn, yellow corn and black corn; according to its shape, structure of endosperm and presence or absence of glume, it can be divided into hard grain type. Semi-horse type, sweet type, etc., as well as by quality points, can be divided into waxy corn, sweet corn, high oil corn and so on. When we conduct comparative experiments on corn, that is, to study the germination rate of corn, or different types of corn, growth status and yield rate, we often need to use a counting instrument, or an automatic counting instrument. The particle meter is specifically designed to count the seeds of rice (middle grain), rape, vegetables, flowers, and tobacco crops in order to obtain the data we need. Of course, the number of different types of grain analyzers can vary depending on the types of crops, such as the SLY-A automatic counting instrument, the specific number of rice (middle grain), rapeseed, vegetables, flowers, tobacco (small grains) and other medium and small seeds, SLY- The B automatic counting instrument is designed to count large seeds such as corn, soybean, and sunflower seeds, while the SLY-C automatic counting instrument combines the features of the SLY-A automatic numbering instrument and the SLY-B automatic numbering indicator. grain.
Corn is a natural cross-pollination crop. In addition, the production conditions and processes are more complicated, and there are more opportunities for seed-borne mechanical intermixing and natural intermixing. Practice has proved that, in addition to conscientiously implementing safe and reliable isolation, the specifications are correct and seeded, strictly eliminating miscellaneous and inferior, timely and thorough deciphering, and collecting the five technologies of panning and picking, we must also do a good job in breeding the original species. The lineage is purified and rejuvenated, and the seeds of the inbred lines on the production are regularly replaced with high-quality seeds. This is a fundamental measure to ensure the quality of hybrid seeds.
The following describes the method of purification and rejuvenation of inbred lines.
First, the method of isolation of ear (also known as the method of selecting the ear line)
This method is suitable for higher purity inbred lines. In the fall, excellent and strong, full, disease-free pests are selected from the breeding grounds. In the spring of the following year, the isolated plots will be selected. Each ridge will be planted with a ridge, and the seeds will be strictly removed after emergence. Pull out the tassels of mixed or suspected ear lines before tasselling. The hybrid lines in the typical ear line must also be strictly eliminated. During the autumn harvest, the most typical ear lines left from the election should be selected to have the same length and ear type. The typical ear is left as the seed for seed selection in the next year. From the rest of the reserved ear rows, the mixed suspect ears were eliminated and then mixed and threshed for large-scale breeding or hybrid breeding in the following year. The ear line selection process is best documented on a row-by-line basis for seedling color, tasselling period, filament color, plant height, uniformity, maturity, and pest and disease status, and is used as the basis for selection or elimination during autumn harvest.
Second, a panicle purification method
In order to maintain the superior cultivar of the original inbred line and improve the typicality of the existing inbred line, the propagation method of the first panicle propagation can be used. Given that the typical inbred lines and the combining ability of different breeding units are not the same, it is better to introduce a typical ear directly from the original breeding unit as the primary species of one ear. In the first year: In the isolation and propagation area of ​​the first pass, the typical ear individual seeding introduced by the breeding unit should pay attention to miscellaneousness and inferiority before flowering after emergence, and then select the self-crossed 5 spikes - 10 spikes of the planting bag. After the fall, one of the best seedlings was selected and reserved for the second year of the first ear propagation. From the remaining hundreds of ears, 50 to 100 typical panicles were selected and saved as earings for the next year. Selection of species. In the second year: continuing in the first propagation area, single seed and seedlings were self-crossed with 5 spikes - 10 spikes; in the ear line breeding area, 50 were selected for use in the first year - 100 typical panicle branches were planted, and they were propagated and selected according to the requirements of the panicle line selection method. In the autumn, from the first propagation area, select one of the best typical self-interested spikes and 50 to 100 typical spikes that are not bagged, and select typical ear rows from the ear line breeding area. Spikes are mixed and threshed, or they are threshed according to the ear, and they are given to different units as the original species of inbred lines for breeding or breeding. In the third year: According to the second year's practice, the first-pass propagation area, the ear line breeding area and the inbred line original breeding area were set up respectively. Grading and continuous seed selection allow the existing inbred lines to be purified quickly.
The above describes how to purify corn seeds because corn seeds are easily mixed with other seeds during harvest and storage, resulting in impure seeds. This will affect the seed classification at the next sowing, so seed purification is a very important step in the storage of seeds. Next, let's take a look at what treatment corn seed should be taken before sowing so that the seeds have the highest germination rate.
A. ABP rooting powder soaking. ABP rooting powder is an efficient, broad-spectrum rooting accelerant. Before sowing, corn seedlings were soaked with ABP4 rooting powder 15-20 mg/kg solution for 6-8 hours, so that the seeds emerged early and homogeneous, the roots were developed, the plants were robust, and the yield increased by 11.3%.
Second, brassinolide soaking. Also known as Brassinolide, abbreviated as BR, is a new type of plant stalk conditioner. After soaking seeds with corn in 0.3-0.5 mg/kg brassinolide solution for 12 hours, it can sow seedlings and accelerate seedling growth. Increase the resilience, can increase production 8.5-14.1%.
Third, soaking with sodium nitrate. Sodium nitroprusside is a new and highly efficient plant growth promoter. Soaking seeds with 6 mg/kg sodium nitric acid solution for 8-10 hours prior to sowing can achieve early emergence, accelerate growth and development, increase resistance, and increase production by 10%. about.
Fourth, biological potassium fertilizer seed dressing. Bio-potassium fertilizer is a bio-fertilizer developed by using silicate bacteria. It has the effect of activating potassium, phosphorus, and magnesium, iron, silicon, molybdenum and other nutrients in the soil. Before corn sowing, 667 square meters of biological potassium fertilizer 500 grams of water 250 ml, after the open and the seeds mix well, after a little dry and sowing, can enhance corn drought resistance, lodging resistance, reduce disease and prevent premature aging, promote large spikes and more, Increase production by 10.4%-17.8%.
Fifth, compound titanium fertilizer No. 1 seed dressing. Compound titanium fertilizer No.1 is a high-tech product with titanium as the main component and is equipped with trace elements and organic matter. 667 square meters of compound titanium fertilizer No. 1 50 mg plus 500 ml of water mixed with corn seeds can promote nitrogen in the soil of plants. Absorption and utilization of phosphorus and other elements, enhanced photosynthetic efficiency, increased stress resistance, an average yield increase of 13.3%.
Six, SA-1 water absorbent seed dressing. SA-1 Water Absorbing Agent is a high water-absorbing resin. The seed dressing can increase the soil water holding capacity. When the dry land or the moisture content is insufficient, the yield increase effect is significant. The corn can increase the production by 8% to 15.4%. The first net seed is used to soak the soil and the mixture is mixed. For the water-absorbing agent with a seed weight of 1.5% to 2%, make it adhere evenly, dilute and dry it for drying.
Seventh, the root protection seed coating agent. Root protection seed coating agents are systemic insecticides. Fungicides and nutrients, plant growth regulators and other scientific preparation. Before sowing, corn is coated with seeds at a ratio of 1:40 according to drug species, which can effectively control underground and seedling pests, and at the same time prevent virus diseases, head smut, stem rot, etc., prompting Miao Qi to grow strong and strong. Early onset, increased production by 9.4%-18.3%.