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【Objective】Rice lodging resistance is an important trait in current rice breeding. The systematic evaluation of lodging resistance of germplasm resources is of great significance for breeding lodging-resistant varieties.【Method】200 germplasm resources in China were taken as materials, 9 traits related to lodging resistance of rice were systematically investigated, and the breeding value of these traits was evaluated by morphological clustering and path analysis.【Result】According to the lodging index, the tested materials were divided into three types: high fall-resistant type, fall-resistant type and lodging type, among which 81.5% of breeding resources had good fall-resistant ability. The correlation coefficient between stalk physical traits and lodging index of different lodging resistant germplasm resources was significantly different. The plant height, bending moment and second pitch length of restorer were positively correlated with lodging index, and the correlation coefficient between bending moment and lodging index d lodging index reached 0.789. The folding resistance of base and sheath leaf thickness were negatively correlated with lodging index, and the correlation coefficients were-0.754** and-0.659**, respectively. There was a significant positive correlation between plant height and basal segment length and lodging index, and the correlation coefficient between plant height and lodging index was 0.681**. The correlation coefficient between buckling resistance and lodging index was-0.841**.The path analysis results showed that the bending moment of the restorer line and other materials had a direct positive effect on the lodging index (Py=0.519), the plant height of the sterile line had a direct positive effect on the lodging index (Py=0.737), and the base bending force of both parents had a direct negative effect on the lodging index, with direct path coefficients of-0.331 and-0.702, respectively.【Conclusion】The lodging resistance of rice is a complex trait, and different germplasm resources have different lodging resistance characteristics. Scientific utilization of breeding resources is the key to rice lodging resistance breeding. [ABSTRACT FROM AUTHOR]

[Objective】 To understand the condition of water bodies of the rice-fishery complex systems in saline areas, the response relation- ships between nutrients and their morphological transformations and water environment factors were investigated. 【Method] From April to September 2021, water samples were collected at 35 sample sites, and 10 aquatic environmental factors and 6 forms of nutrients were deter- mined in the system. Correlation analysis, stepwise regression and path analysis, gray correlation analysis and redundancy analysis (RDA) methods were applied to study the relationships between nutrients and their morphological transformations and aquatic environmental factors. [Result】 The main factors affecting nitrogen of the rice-fishery complex system were alkalinity, CODMn, pH and water temperature in saline areas, the main factors affecting phosphorus were COD Mn, water temperature and alkalinity, and the main factors affecting total potassium were conductivity, TDS, Chl. a, alkalinity, salinity, CODMn and water temperature. Alkalinity, CODMn, pH and water temperature were the main factors affecting the transformation of nitrogen forms of the rice and fishery complex system in saline areas. CODMn, water tempera- ture, alkalinity, conductivity, salinity, Chl. a and pH were the main factors affecting the morphological transformation of phosphorus. There- fore, the main influencing factors of nutrient elements of the rice-fishery complex system were alkalinity, CODMn and water temperature in sa- line areas, and the main influencing factors of nutrient morphological transformation were alkalinity and pH. The main influencing factors of nutrient elements and their morphological transformation of rice-fishery compolex system were relatively consistent in saline areas, the main factors were alkalinity, CODMn, pH and water temperature, among which CODMn was positively correlated with nutrients. and water tempera-ture was negatively correlated with nutrient elements. Alkalinity and water temperature mainly inhibited the rise of nutrient elements, while COD Mn could promote it. [Conclusion] The water temperature of the rice-fishery compolex system is suitable in saline areas, and the salinity can improve the alkalinity of the water body, which has a positive effect on inhibiting the increase of nutrient content, but with the operation of the system, COD Mn will increase, and certain measures need to be taken if CODMn increases excessively. [ABSTRACT FROM AUTHOR]

[Objective] The single cross of maize sister lines can increase its seed production. Because of seed production is the result of multiple agronomic traits of the parents, it is important to reveal the relative importance of each trait to yield for the selection of suitable sister lines. [Method] The relationship among 15 main agronomic traits and yields of the maize inbred line ZOL-1 sister lines was analyzed by grey correlation analysis, correlation analysis and path analysis. [Result ] Grey correlation analysis showed that the order of the influence of 15 traits on yield was rows per ear > ear diameter > kernels per row > plant height > ear length > ear height > days from emergence to silk > three leaves area near ear > bare top length = leaves per plant> days from emergence to pollen > 100-kernel weight> shelling percentage > green leaves at harvest> days from emergence to tassel. Correlation analysis showed that the traits that were significantly positively correlated with yield were kernels per row, ear length, plant height, ear diameter, rows per ear, and three leaves area near ear, the traits showing a significant positive correlation were ear height and 100-kernel weight. Path analysis showed that the direct effect of each trait on yield was kernels per row > rows per ear > 100-kernel weight > plant height > ear diameter > three leaves area near ear > days from emergence to tassel > ear length > leaves per plant > days from emergence to pollen > shelling percentage > days from emergence to silk > bare top length > ear height > green leaves at harvest. [Conclusion] Plant height, ear diameter, ear row number, and kernels per row were the main factors affecting the yield of the sister lines of the maize inbred line ZOL-1, which could be used as reference indicators for the selection of maize sister lines and hybrid hybrids. [ABSTRACT FROM AUTHOR]

[Objective]The study on the correlation between main agronomic characters and yield of Brassica juncea in Guizhou will provide theoretical guidance for breeding research. [Method] Through correlation and path analysis, the relationship between main agronomic characters and yield of 269 local B. juncea in Guizhou was studied. [Result] The number of effective pod per plant, the number of secondary effective branches, the number of pod per main inflorescence, plant height, the number of primary effective branches and the number of seeds per pod were significantly positively correlated with the yield, and the 1000-grain weight was significantly correlated with the yield. The direct path coefficient indicated the effect degree of different agronomic traits on the yield of B. juncea, which showed that whole plant effective pod number (x8) > 1000-grain weight (xlO) > plant height (xl) >secondary effective branch number (x5) > main inflorescence pod number (x7) > per pod number (x9) > branch angle (x6) > effective branch height (x2) > primary effective branch number (x4) > main inflorescence long (x3). [Conclusion] The number of effective pod per plant, secondary effective branches, pod per main inflorescence, the plant height, the number of primary effective branches and 1000-grain weight were the main factors affecting the yield. The secondary effective branch number had a great contribution to the whole plant pod number, and had a great positive effect through the whole plant pod number. Therefore, the selection of pod number and secondary effective branch number should be emphasized in high yield breeding of B. juncea. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to analyze the main factors affecting the yield of Brassica napus L in different regions of Sichuan province, so as to provide theoretical basis for breeding B. napus L. varieties suitable for different rapeseed producing areas in Sichuan province. [Method] Variation analysis, correlation analysis and path analysis were used to analyze the relationship between the agronomic characters and the yield of B. napus L . [Result] In Xindu, Deyang and Dazhou regions, the most variation of agronomic trait was the first branch numbers. The value was the number of seeds per siliquain Chongzhou and Mianyang regions. It was the number of effective siliqua per plant in Nanchang, Yibin, Jianyang, and Leshan regions. The least variation of agronomic traits was the plant hight, in the Xindu, Chongzhou, Jianyang, Mianyang, and Deyang regions. It was 1000-seed weight, in the Nanchang, Yibin, Leshan, and Dazhou regions. The yield of Xindu region was significant or highly significant negative correlated with the first branch numbers and the number of effective siliqua per plant But, it was significant positive correlated with the plant hight and the number of seeds per siliqua. The yield of Nanchang region was significant or highly significant positive correlated with the plant hight, the first branch numbers, and the number of effective siliqua per plant. The yield of Yibin region was highly significant positive correlated with the plant hight. The yield of Jianyang region was significant or highly significant positive correlated with the number of effective siliqua per plant and the number of seeds per siliqua. But, it was highly significant negative correlated with the 1000-seed weight. The yield of Leshan region was significant positive correlated with the number of effective siliqua per plant. There was no significant correlation between yield and main agronomic traits in Mianyang, Deyang, and Dazhou region. In Xindu region, the greatest direct path coefficient and the greatest comprehensive effects were respectively the number of seeds per siliqua and the the number of effective siliqua per plant. Those were both the number of seeds per siliqua in Chongzhou region. In Nanchong and Jianyang regions, the greatest direct path coefficient and the greatest comprehensive effects were respectively the number of seeds per siliqua and the 1000-seed weight. Those values were respectively the number of effective siliqua per plant and the first branch numbers in both Mianyang and Dazhou regions. In Deyang region, the greatest direct path coefficient and the greatest comprehensive effects were both the number of effective siliqua per plant. [Conclusion] There were differences in the coefficient of variation of main agronomic traits of B. napus L in different producing areas of Sichuan province, and there were differences in correlation with yield. The effects of yield components on yield should be fully considered in breeding, as well as the comprehensive effects of other traits. The present study provides a scientific basis for breeding B. napus L varieties suitable for different regions of Sichuan province. [ABSTRACT FROM AUTHOR]

[Objective] In order to select micro-endosperm maize with high oil content, understand the effects of quality and yield traits on oil content of micro-endosperm maize, correlation and path analysis of main quality and yield traits of micro endosperm oil maize were studied. [Method] Two micro-endosperm corn inbred lines with high oleic acid and high oil percentage and six micro-endosperm corn inbred lines with low and medium oleic acid and low and medium oil percentage were selected in this experiment, and 12 cross combinations of micro-endosperm corn were designed according to NC II, correlation and path analysis of main quality and yield traits were studied. [Result] The crude protein content of maize meal of 12 micro endosperm maize hybrid combinations were 27. 67% -33. 33%. The highest crude protein content was combination 11, and the lowest was combination 8. The oil percentage of micro endosperm maize hybrid combinations were 24. 54% - 28. 95 %. Combination 11 had the highest oil percentage, and combination 6 had the lowest oil percentage. The content of oleic acid varied from 42. 67% to 47. 80%, among which the highest was combination 8, and the lowest was combination 1. The content of linoleic acid ranged from 31.90% to 40.93%, among which the highest was combination 1, and the lowest was combination 8. The content of linolenic acid varied from 0. 64 % to 0.79%, among which the highest was combination 9, and the lowest was combination 8. Correlation analysis showed that the oil content per ear was extremely positively correlated with the kernel weight per ear and the 100 kernel weight (P < 0.01, the same as below). The kernel weight per ear was positively correlated with the 100 kernel weight There was no significantly positive correlation between the content of oleic acid and the content of crude protein and oil percentage (P > 0.05), but a significant negative correlation between the content of oleic acid and the content of linoleic acid. Path analysis results showed that the direct influence son of the five causal traits on the oil content per ear was kernel weight per ear > oil percentage > linoleic acid content > crude protein content > oleic acid content. The direct effects of kernel weight per ear, oil percentage, linoleic acid content and crude protein content were positive effects, and the direct effects of oleic acid content were minimal negative effects. [Conclusion] There was extremely positive correlation between the kernel weight per ear and the oil content per ear of the micro endosperm maize hybrid combinations, and the path coefficient of kernel weight per ear to the oil content per ear was also the maximum value, which indicated that increasing the kernel weight per ear was the best way to increase the oil content per ear of the micro endosperm maize hybrid combinations. [ABSTRACT FROM AUTHOR]

[Objective] Exploring change dynamics and influencing factors of soil moisture content in rocky desertification area is to provide the theoretical basis for formulating agricultural engineering measures of rocky desertification ecological restoration area and selection of ecological reconstruction model. [ Method] The dynamic change characteristics and influencing factors of soil moisture content are analyzed by using linear regression and path analysis methods and taking the soil treated with organic fertilizer, grass-covering and bare surface in rocky desertification area as the research object based on continuously determining the soil moisture content, air humidity, air temperature, soil temperature and light intensity. [ Result] The response rule of moisture content of bare soil to time change is not obvious. The linear regression equation of moisture content in soil treated with organic fertilizer and grass-covering reaches a very significant level. The total determinant coefficient of all indexes to soil moisture content is 0. 118, with a sequence of air humidity> soil temperature > air temperature > light intensity. [ Conclusion] Organic fertilizer and grass-covering patterns can regulate the range of soil moisture change effectively. The influencing mechanism and contribution rate of different environment condition to soil moisture content in rocky desertification area should be evaluated comprehensively combining with soil type, meteorological factor and landform. [ABSTRACT FROM AUTHOR]

[Objective] To analyze the main growth factors affecting the fruit weight of Tainong No.17 pineapple, and provide a reference basis for its high-quality and high-efficiency cultivation. [Method] Determine the single fruit weight, leaf number, leaf weight, leaf area, and leaf area of ​​Tainong No.17 pineapple. Underground stem weight, suction bud length, support bud length, top bud length, suction bud weight, support bud weight, top bud weight and D leaf (the longest leaf with the best growth potential) area, and perform linear correlation, partial correlation, and recovery Correlation and regression linear path analysis. [Results] The results of correlation analysis showed that the weight of a single fruit of Tainong No.17 pineapple was significantly positively correlated with the number of leaves, leaf weight, leaf area, underground stem weight, stem length and weight (P<0.01, the same below), the degree of correlation is expressed as the number of leaves (r=0.680)> leaf weight (r=0.665)> leaf area (r=0.664)=underground stem weight (r=0.664)> bud weight (r =0.470)> Suspension bud length (r = 0.302), positively correlated with apical bud length and D leaf area but not significantly correlated (P>0.05, the same below), and extremely significantly negatively correlated with suction bud length (r=- 0.312) (P<0.05, the same below), which was significantly negatively correlated with the weight of sucked buds (r = -0.258), and had no significant correlation with the weight of apical buds. The results of partial correlation and multiple correlation analysis showed that the weight of underground stems, the number of leaves, The five growth indicators of leaf area, sucking bud weight, and holding bud weight have different effects on single fruit weight in partial correlation and multiple correlation. The three growth indicators of holding bud length, sucking bud length and leaf weight have different effects on single fruit weight. The degree of influence in partial correlation and multiple correlation is the same. Among them, the degree of positive correlation in partial correlation is in the order of underground stem weight (r=0.218)> bud weight (r=0.179)> leaf area (r=0.064)> suction bud Weight (r = 0.054)> number of leaves (r = 0.049); the degree of positive correlation in the multiple correlation is ranked as number of leaves (r = 2.102)> underground stem weight (r = 1.344)> bud weight (r = 0.718)> The weight of sucking bud (r=0.255)> leaf area (r=0.015); the order of negative correlation degree in partial correlation and multiple correlation analysis is the length of sucking bud> the length of sucking bud> leaf weight. The results of path analysis show that Weight (direct path coefficient=0.485) has the greatest direct impact on the weight of a single fruit, followed by underground stem weight (direct path coefficient=0.419) and leaf area (direct path coefficient=0.318) and the number of leaves (direct path coefficient=0.190); the indirect positive effect of the bud weight through the underground stem weight on the single fruit weight is the largest, and the underground stem weight has the largest indirect positive effect on the single fruit weight through the underground stem weight. The weight of the buds has an indirect positive effect on the weight of a single fruit, and the number of leaves has an indirect positive effect on the weight of a single fruit through the weight of the underground stem and leaf area. [Conclusion] The weight of the underground stem, the weight of the bud, the leaf area and the number of leaves are the influences of the Tainong No.17 pineapple. The main growth index of single fruit weight can be used as a reference for the high-yield characteristics of Tainong No.17 pineapple. In the cultivation of Tainong No.17 pineapple, the increase in underground stem weight, leaf area and number of leaves during the vegetative growth period should be promoted and in the fruit formation stage. Keep the support buds and gradually remove the support buds after the single fruit has been re-formed and stabilized to achieve the goal of high-quality and efficient cultivation. [ABSTRACT FROM AUTHOR]

[Objective] A comparative study was carried out on the photosynthetic characteristics of the early fruiting walnut ‘Nonghe 1’ and the late fruiting walnut ‘Jinlong 2’ .[Method] Taking ‘Nonghe 1’ and ‘Jinlong2’ as test materials, the leaf photosynthetic parameters were determined by Li-6400 photosynthetic instrument, and the relationship between net photosynthetic rate and main environmental factors was analyzed. [Result]The diurnal variation of net photosynthetic; rate for ‘Jinlong 2’ showed a ‘double peak’ curve, and the photosynthetic ‘siesta’ phenomenon was caused by non-stomatal limiting factors. ‘Nonghe 1’ was a single peak curve. Transpiration rate, intercellular CO2 concentration and stomatal conductance of ‘Jinlong 2’ were significantly increased by 27.46 % ,17.78 % and 22.73 % compared with that of ‘Nonghe 1’ (P <0. 05) . Compared with ‘Jinlong 2’ , the net photosynthetic; rate, water utilization rate and stomatal limit values of ‘Non-ghe 1’ were significantly increased by 20. 00 % ,45.40 % and 42. 40 % (P <0. 05 ). Path analysis showed that photosynthetic effective radiation was the main decision-making factor in affecting the diurnal change of net photosynthetic; rate of ‘Nonghe 1’ and ‘Jinlong 2’ . Air relative humidity and air CO2 concentration were the main limiting factors of ‘Jinlong 2’ and ‘Nonghe 1 ’ respectively. [Conclusion] Early walnut ‘Nonghe 1’ had stronger photosynthetic; capacity than late walnut ‘Jinlong 2’. Photosynthetic; effective radiation is the main environ-mental factor in affecting the net photosynthetic rate of early and late fruiting walnut. In the production, appropriate plant spacing and reasonable pruning can be adopted to promote ventilation and light transmission. [ABSTRACT FROM AUTHOR]

【Objective】 In order to provide the theoretical basis for breeding of vegetable faba bean, the direct or indirect effects of major agro¬nomic traits on freshi grain yield of early-matiare and autumn-sowing faba bean and the coefficient of determination were determined.【Meth- od】Thirteen cultivars of early-mature and autumn-sowing faba bean were used to carry out the correlation and path analysis of 15 major agro¬nomic traits to 2 kinds of fresh yield.【Result】 The results showed that the coefficient of variation (c. G ) of seed per plant, pod per plant, nodesof having pods,100fresh seed weight andwidthoffreshpod were 28.57 ', 19.56', 18.56', 17.51 ' and17.39', respec¬tively. These traits could be improved by breeding or farming practices. The largest c. G. of yield was cotyledon yield followed by yeed yield. Number of effective branches, nodes of having pods, pods per plant and seed per plant had extremely significant correlation with yield of fresh pod. The rate of producing cotyledon had extremely significant correlation withi yiel(d of freshi cotyledon. Yield of fresh cotyledon and pod had significant correlation with each other. Path analysis showed that both number of effective branches, pods per plant had positive di¬rect effect and had extremely yignificant correlation with yield of fresh pod. Bothi of thiem should be the main traits in breeding programs, se¬ lection should be based on the characteristics of thie traits which we were more interested in. Rate of producing cotyledon affected cotyledon yield.【Conclusion】 Among all the yield traits, pod yield showed significantly lower variation and should be the focus of our breeding program in Yunnan province. When yield of pod was the target of breeding, number of effective branches and pods per plant should be the main se¬ lecting traits combining with nodes of having pods and seed per plant. When yield of cotyledon was the target of breeding，rate of producing cotyledon was the main selecting trait [ABSTRACT FROM AUTHOR]