First, tillers and effective panicles

1978, 1979 autumn, we investigated the high-yield situation of hybrid rice in Longhai, Pinghe and other counties in Fujian, and got a relatively complete grasp of the data of 52 fields, combined with the data of 388 fields accepted by the local agricultural bureau; The data of 197 plot with the difference between theoretical yield and actual yield within 3t5kg/ha were selected for statistical analysis. Results The partial correlation between the yield of Shanyou 2 and Siyou 2 in early and late seasons and the total grain number reached a significant level (formula omitted). The standard partial regression coefficient was calculated according to the number of panicles and the number of grains per panicle, which showed that the yield-increasing potential of increasing panicles was greater than that of increasing grains. We also investigated the relationship between effective panicle number and yield of hybrid late rice in 6 regions 1 1 counties in this province. The effective number of panicles with yield less than 350 kg per hectare is135 ~1800,000. 225-24 million people produce 6250 and 6000 kilograms per hectare, and 270.28 million people produce 6750 and 7500 kilograms per hectare; 9750, 12000 kg, the output per hectare is 3 million and 3.45 million. This shows that more effective panicles have high yield and less ineffective panicles have low yield. The data analysis of 197 plot showed that the basic number of seedlings, the highest number of stems and the ear integration rate were significantly or extremely significantly positively correlated with the effective number of ears, respectively.

(1) The quality of 19T7 seedlings and seedlings of Crotalaria were studied. Honda's two treatments: seedling quality and nitrogen application rate. The yield of the test results is obviously different. Four of them were analyzed as follows: 2 Platanus acerifolia seedlings, 265,438+00 kg n/ha, 1 Platanus acerifolia seedlings, 65,438+005 kg/ha, 3 Platanus acerifolia seedlings, 265,438+00 kg/ha and 5T99.75 kg/ha. 5649.75 kg/ha single-stem seedlings used 1, twice as many seeds and l times as much nitrogen fertilizer as binary and trigeminal seedlings, and only increased 150 kg and 24. 5 kg/ha. According to the experimental materials, the effective panicle number of two-branch seedlings is 365438 0.8% less than that of three-branch seedlings, while the number of full grains per panicle is 5% more. Therefore, multi-branch seedlings have the functions of saving seeds, saving fertilizer and increasing yield with large panicles. We also analyzed the ratio of spikelet yield at each node. The results showed that the 2/o and 3/O ears of clover accounted for 46% of the total ears, and the yield accounted for 49% of the total output. Multiple seedlings 5/0, 6/0, 7/. The yield of three-section cracked cotton accounts for 82% of the total output. The former is low-slung cotton with large panicle and many grains. The latter is divided into middle nodes, with smaller ears and fewer grains. Mo Jiarang pointed out that the chlorophyll content of multi-branch seedlings was 16. T8~4 1.65% is higher than that of harmless seedlings. From emergence to yellow maturity, the photosynthetic potential of multi-branch seedlings is 9~33% higher than that of non-millet seedlings, and the root system is also developed. In this way, the developed multi-branch seedlings absorbed the amino acid transport synthesized by photosynthetic products of leaves with high nitrogen and chlorophyll content. In the early stage, the diversity was promoted, and the mulberry stand advantage was formed. In the mature stage, the young panicles differentiated into strong stalks and big panicles, forming the panicle-grain advantage.

(2) 19T The maximum number of lotus roots, stems and sunflowers in the field is 4.05-5.4 million /hm2. In this range, the highest number of stems and weeds are positively correlated with the number of effective panicles. The ratio of seedlings, plants and panicles in 69 fields with yield above 100 kg/ha is 1, 3,2, that is, 24,2 per hectare. To achieve this population dynamic index, we must first cultivate robust multi-branch seedlings, and on this basis, carry out fertilizer and water management according to the habit of field isolation of hybrid rice. From 19, we observed the ramet habit of weeds in Siyou No.2 field for 8 years. The results showed that: 1, the primary differentiation rate of weeds was 98%, distributed in nodes 1/0 and 9/0. The ear formation rate of the second separation was 40%, which was distributed in 2/0 "5/d node. The rate of ear formation in the third division is zero.

2. The development of Finney is greatly influenced by nitrogen and carbon nutrition. The number of grains per panicle in Honda was the highest in the 7th section, which was born in 5/7. The first topdressing was carried out on April 28th, and carbon front and calcium superphosphate131.25kg were applied per hectare. According to the climatic conditions at that time, it took about 6 or 7 days to be absorbed by rice roots. This shows that the growth of 7/O node is closely related to nitrogen nutrition. When there are more than three leaves at jointing stage, it can generally become an ear; However, if there is a "big wind" before starting the machine, these weeds will die because of insufficient light. On the contrary, the population was "sparse" at heading-filling stage, the light transmittance at the base increased, and the axillary buds at the base of the plant germinated again. All these indicate that the growth and death of hybrid rice are closely related to carbon nutrition. 3. Partial correlation analysis showed that the node position was negatively correlated with the number of effective panicles at each node, that is, the lower the node position, the more effective panicles there were. The above clean fruits can be used as the basis for Honda's seedling raising, fertilization in the whole field, transplanting seedlings and fertilizer and water management.

Second, the number and weight of grains per spike.

1979 investigated the ear development of Shanyou 3 and IR66 1 (omitted). The number of undifferentiated spikelets, Ying Shi heading flowers or full grains per panicle of Shanyou No.3 was higher than that of IR66 1. However, the spikelet degeneration rate was 9.4% higher and the seed setting rate was 9. 1% lower. Therefore, in production, it is necessary to promote and protect flowers, to promote large panicles, to reduce degradation and to improve seed setting rate. According to the data analysis of 197 plot, the partial correlation between yield and seed setting rate reached a significant level, and the total number of grains was negatively correlated with seed setting rate, which also showed the importance of keeping flowers and improving seed setting rate. The main factors of low spikelet setting rate are: 1, insufficient nutrients and uneven distribution. In 1979, we used Siyou 2 and Hong410 (control) as materials, and selected 20 normal main spikes to observe the growth potential of spikelets in different parts. Results The percentage of strong flowers in Gongyi Siyou No.2 was 4.9%, which was 2.05% lower than that in Hongpao 10. The middle flower is 45.0%, which is 2.5% less than the control. The inferior flowers were 65438 02.2%, which was 5.45% more than that of L-Bi control. It shows that the low seed setting rate of hybrid rice is caused by weak flowers. Different grades of spikelets have different seed setting rates. The effect of spikelet cutting on seed setting rate of Siyou 2 was observed for 9 consecutive years. The seed setting rate of the first spikelet was 93.3%, and that of the second spikelet was only 49%. After cutting off the second spikelet, the seed setting rate of the first spikelet increased to 96.3%. After cutting off the first spikelet, the seed setting rate of the second spikelet increased to 90%. The results showed that the low seed setting rate of spikelets in secondary branches was caused by insufficient nutrients and uneven distribution. 198 1 year, the results showed that the photosynthetic efficiency and daily increase of dry matter of hybrid rice planted in early or late season were the largest from green turning to young panicle differentiation, followed by young panicle differentiation to heading, and the smallest from heading to maturity. This conclusion is consistent with Cao Xianzu's report. This is a physiological phenomenon of hybrid rice. It can also be seen from the study that the average daily temperature from emergence to young panicle differentiation is 28℃, and the amount of sunshine and solar radiation is 25.09 calories/cm, 15 for late season sowing (6/ 18 sowing,15 transplanting and15 harvesting). Therefore, the diversity block has a large leaf area (1.4 times as large) and daily weight gain of dry matter, which provides a lot of energy for spike (sink) development. After heading, photosynthetic efficiency decreased rapidly (by 40. 0%), the accumulation and transformation of dry matter per unit volume are at a disadvantage, but the vegetative body of the plant is large, and the total dry matter accumulation is still large when planted in early season. Therefore, the effective panicle planted in early season increased by 589,500/ha, the number of grains per panicle increased by 65,438 0.04, the seed setting rate increased by 6.88%, the 1000-grain weight increased by 4.98 g, and the yield increased by 65,438 0.75 kg/ha. In addition, it can be seen from the results of late topdressing experiments of Wei You No.2 and Julu No.2 that under the condition of applying nitrogen 150 kg per hectare, the dry weight, activity, chlorophyll content (0.0 19%), photosynthetic potential and photosynthetic rate of canopy leaves can be significantly improved by extracting 23% (5 kg urea per hectare) at booting stage. The above shows that the decrease of photosynthetic efficiency in the middle and late stage of hybrid rice leads to insufficient nutrients, more weak spikelets and low seed setting rate. Late topdressing can change this shortcoming and improve the seed setting rate. 2. Affected by ecological conditions. There are two sources of nutrients for grain filling after spikelets are affected. One is that carbohydrates stored in stems and leaf sheaths before heading are transported to the ear; The second is the product of photosynthesis of canopy leaves after heading. 1978 According to the sowing data by stages, due to the different environmental conditions after heading, the ratio of the two is different, which can be divided into three types: (1) The average temperature is about 28℃ in 20 days after heading, the sunshine rate is 75%, the relative humidity is 80% in 7 days, and the filling maturity is short (3 1~35 days); Nutrients before heading accounted for 365,438+0 and 39%, and nutrients after heading accounted for 69 ~ 665,438+0%. (2) Twenty days after heading, the average temperature was 26 and 28℃, the sunshine rate was 47 and 5 1%, and the relative humidity was above 85%; Nutrients accounted for 42~60% before heading and 40% after heading. (3) 20 days after heading, the average temperature was 20.87℃, the sunshine was sufficient, the relative humidity was below T9%, and the filling maturity reached 5 1 day; The nutrients before heading and after heading accounted for 28% and 0.2% respectively. The results of seed test showed that the rice panicle with high temperature, sufficient light and suitable humidity had short filling maturity, but high seed setting rate, full grains, large 1000-grain weight and high yield. Low temperature, sufficient sunlight and low humidity will lead to low seed setting rate and incomplete seeds. High temperature, much rain, little sunshine and high humidity will affect the seed setting rate and seed plumpness. This is the influence of climatic conditions on the development of panicles and grains of hybrid rice after heading. Therefore, it is the key to improve the seed setting rate to adjust the sowing date and transplanting date so that reproductive health can give full play to its advantages under the best light conditions. The results of temperature treatment of Siyou No.2 in 8 ~ 19 years showed that the seed setting rate decreased from branching differentiation to low temperature treatment at flowering stage (19℃). The harm degree of low temperature treatment for three days to fruiting is: meiosis period of pollen mother cells >; No matter heading, flowering or filling, the seed setting rate and 1000-grain weight decreased when treated at 35℃ or 40℃ for 3 hours. Pollen aborts and does not fertilize when it encounters high temperature above 35℃ during heading and flowering; High temperature during grain filling affected the transportation of photosynthetic products and formed deformity. Shading or raining at flowering stage will reduce the seed setting rate, and the seed setting rate of strong flowers will drop from 87% to 58' 4%. Due to the unsynchronized development of panicles and spikelets in rice, the seed setting rate was increased from 65. 1% and 5D% to 78% and 62% respectively when the heading and flowering period were treated at 35℃ and 40℃ for 3 hours.

Third, root development and leaf growth.

The research results of root system development: Siyou No.2 and Shanyou No.3 are larger in root number, root diameter and root dry weight than those of conventional rice red 4 10 and short spike type big guy (slightly smaller than the long spike type big spike variety 3 kg 70 reed), and have stronger rooting ability and root activity. The dry weight of roots is the largest at yellow maturity. The rooting force can last until the early booting stage, and the root activity reaches its peak at the yellow maturity stage. The "floating roots" of hybrid rice are developed. Floating roots start from 1 1/0 leaves and continue to mature. The roots of Siyou 2 and Shanyou 3 can reach five times, while those of 4 10 and Big Guy are only two or three times. Winnie et al. [7] reported that the absorption capacity of floating roots is 2-3 times higher than that of ordinary roots. Kawada Pinpin "J" reported that the occurrence of high-order rooting was synchronized with spike branches and spikelets. Therefore, the development of floating roots is closely related to the big spikelet of hybrid rice. Under water layer irrigation condition F, hybrid rice has a large number of roots, thick roots, dry weight and developed floating roots, but there are more yellow roots, brown roots and black roots in the later stage, and almost no white roots can be seen. The root system and dry weight of dry farming are small, and there are many white roots without floating roots; Wet irrigation is somewhere in between. This conclusion is consistent with the reports of Das, D.K. and others. Different combinations have different sensitivities to water shortage, and Siyou 2 is greater than Shanyou 3. In the early, middle and late stage of water layer irrigation, the root quantity, dry weight, root diameter and floating root quantity are large and developed. One day after harvesting, the roots in O and 20cm soil layers are yellow-brown, and the roots in 20 and 40cm soil layers are yellow-white, so the roots are elastic. Therefore, reasonable irrigation can improve the soil environment, give full play to the root advantages of hybrid rice, and lay the foundation for multi-panicle, large panicle and high seed setting rate. The root development of hybrid rice is closely related to the growth of aboveground parts. The maximum root growth per unit time appears at the peak of diversity, the maximum root dry weight per unit time appears at the invalid branch and death stage, followed by the maximum stem flow intensity. The results showed that hairy roots of hybrid rice grew rapidly in the early stage of growth. Second, the root system of rice is thicker, the content is rich and the dry weight is increased; Third, the exertion of root activity. This development process of root system can be used as the basis of fertilizer and water management. The results of root cutting test show that 4/0 "8/. Root cutting at leaf stage, that is, cutting off the roots of 1/0 and 5/0 nodes, significantly reduced the number of branches and effective panicles; Root cutting at 12/0 leaf stage reduced the number of filled grains per panicle and seed setting rate; Root cutting at 14/0 and 16/0 leaves affected seed setting rate and grain weight. To sum up, the rooting ability is the strongest in the stage of emergence-panicle differentiation, and "floating roots" appear; During cultivation, shallow water should be used to fertilize the feet, promote vegetable division and increase the number of ears. Ear differentiation-a large number of floating roots appeared at full heading stage, with great root activity and rapid root dry weight growth; Should be properly shelved, full of fertilizer to promote large ears. The root system is vigorous at full heading stage and mature stage, so wet irrigation and fertilization are needed to improve the seed setting rate and grain weight. In terms of leaf growth, the main stems and leaves of Siyou No.2 and Shanyou No.3 can be divided into three categories: (1) 1/0,10 (1l/0), including leaf sheath-node-branch (missing node), all of which are vegetative growth periods. (2) 1 1/0, 12/0( 12/, 13/0), including leaf sheaths (without nodes and internodes), occurred and grew in the transitional period. (3)13/0 ~15/0 (14/0 ~16/0) nodes, including leaf sheath-node-internode (lack of diversity), all grow in the reproductive period. According to the shape, accumulated temperature, service life and functions of main blades, the blades can be divided into four groups. (Table 1) 1980 Research results on the relationship between roots and leaves of hybrid rice and yield factors: the main stem is cut off by 4/0, 1. /O leaves affect the node segregation of 1~7/0; Rooting in 4/0~8/0 leaf stage (cutting off 1/0 and 5/0) will affect the division of 1/0 and 5/0; Cut off 4/0~ 10/O leaves or 12/O leaves (cut off 9/O nodes), which seriously reduced the number of grains per ear; Cutting 14/O~ 16/O leaves or 12/O stage seriously reduced the seed setting rate. These relationships among leaves, roots, ears and grains of rice can be used as a reference for diagnosis and management at seedling stage. In addition, from the two-year sowing experiment and sowing date study, it can be seen that the medium-mature hybrid rice belongs to the basic vegetative growth type and has temperature sensitivity. During the growing period, the average daily temperature is between 65438±0T and 28℃. With the increase of 1℃, the vegetative growth period was shortened by 5 days, and the main period of daily average temperature was stable at 27~28℃. The safe heading temperature is 23℃. The active accumulated temperature of Siyou No.2 in the whole growth period is 306 1℃, and the active accumulated temperatures in the leaf stages of 1/0 and 16/0 are 173 1℃. —Heading date is 380℃. Heading maturity is 905℃. The accumulated temperature index of young spike is 36.09, the meiosis period of pollen mother cell is 56.45, and the heading period is 68.9. These conclusions are consistent with the report of Shaoxing Basic Group of Zhejiang Academy of Agricultural Sciences (19 0). In a word, medium-mature hybrid rice belongs to the vegetative growth type of temperature-sensitive basal wood, which has three advantages: strong splitting ability, developed root system and more grains per panicle. The three advantages are interrelated, and cultivating many strong seedlings is the basis of giving full play to the three advantages. Adjust the sowing date according to the active accumulated temperature and growth accumulated temperature index, so that the reproductive growth period is in the best period of light, temperature and humidity, which not only enables the nutrients stored in stems, sheaths and leaves to be smoothly transported to the ear, but also facilitates the ear development. According to the relationship among leaves, grasses, roots, panicles and grains, we should carry out fertilizer and water management, coordinate and promote the preservation of mulberry and vegetables, promote the preservation of flowers, and achieve the goals of full panicles, more grains, full grains and high yield.

conclusion

(1) Hybrid rice has three advantages: strong diversity, developed roots and more grains per ear. How evil is the foundation. It has the functions of saving seeds, fertilizer, multiple roots, strong stalks and large panicles to increase production.

(2) Node position was negatively correlated with effective panicle number. The output of 2/O and 3/O accounts for 49% of the total output. The occurrence and growth of vegetable separation are closely related to carbon and nitrogen nutrition.

(3) Hybrid rice has large panicles and many spikelets, but the seed setting rate is not high. The reason is that the killing point is insufficient, and the adaptability of flowering period to temperature and light is narrow.

(4) Many roots, heavy roots and developed "floating roots". The maximum dry weight of hairy roots and roots appeared at the peak of branching and booting stage respectively. The maximum bleeding intensity is in the yellow ripening stage. In the early stage of water layer irrigation, the middle stage of field drying and the late stage of wetting, the root system is developed and there are many white roots.

(5) Hybrid rice can be divided into four leaf groups: 1/0 and 3/0 are seedling leaves, which determine seedling quality; 4/0~9/D( 10/0) is the stage of leaf separation, which determines the separation and the number of ears; 10/0 (110) ~12/o (13/0) is a one-stage defoliation, which affects the dry weight of internodes and the number of grains per ear. 13/0 (14/0) ~15/0 (16/0) is the leaf in the ear development stage, which affects the seed setting and grain weight.

(6) The accumulated temperature index of growth in the young spike differentiation stage is 36.09, the meiosis stage of pollen mother cells is 56.45, and the heading stage is 8.9.

(7) There is a significant partial correlation between total grains and yield. Statistical analysis showed that "Siyou No.2" and "Shanyou No.31"increased the number of panicles on the basis of a certain number of panicles, so as to increase the total number of grains and increase the yield. The population structure of high-yield fields is based on the ratio of seedlings to panicles of 1, 3,2.

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