混合选择对油菜隐性核不育系群体产量及品质性状的改良效应

为了对甘蓝型油菜隐性核不育系的产量和品质性状进行改良,应用群体混合选择改良方法对甘蓝型油菜隐性核不育系混合群体进行多年适度隔离控制轮回选择田间试验。结果表明:1)对构建的两个甘蓝型油菜核不育系混合群体QTA1(黑籽不育系群体)、QTA2(黄籽不育系群体)进行5代混合轮回选择,选育出的2368A和2392A不育系的产量、含油量、配合力均优于原始不育系,芥酸、硫甙等品质指标均优于国家优质油菜标准,含油量达48.34%和49.79%。2)用2368A和2392A与甘蓝型油菜骨干亲本组配了21个比对照油研50增产5.47%～31.34%的核不育两系组合。结论:混合选择改良方法不仅可以改良甘蓝型油菜隐性核不育系的品质和配合力,还可以显著提高其含油量和抗性等。

混合选择对甘蓝型油菜群体产量及品质性状改良效果研究

基于多年适度隔离控制混合群体进行油菜群体的品质和产量性状改良和统计分析,针对人工构建的3个群体QT1(来源于长江流域的油菜品系,含油量大于40%)、QT2(来源于高油分黄籽双低油菜品系,含油量大于44%)和QT3(高油分双低油菜品系,含油量大于43%),经5轮多代的隔离控制混合选择,分析了混合选择群体改良对各油菜群体主要产量及品质性状的改良效应。研究结果表明:油菜产量及品质性状在不同群体及不同轮回间存在真实的遗传差异,主要以单株有效角果数、单株产量、含油量的改良选择效果较好,其遗传增益较大,表明单株有效角果数、单株产量、含油量随选择周期增加呈明显增加趋势,选择效应显著。上述结果表明:应用群体混合选择改良方法可以改善甘蓝型油菜各品系群体的产量性状及品质性状,显著提高改良群体的含油量、油酸、单株有效角果数、单株产量。

不同栽培措施和药剂对油菜茎象甲防治效果及对油菜的影响

研究不同栽培措施和7种药剂对油菜茎象甲防治效果及对油菜农艺和产量性状的影响。结果表明,初春漫灌浇水一次在田间应用和小区试验中对茎象甲成虫的防治效果分别为18.09%和19.91%,为害株率比对照CK分别降低30.37%和32.11%,浇水施肥处理试验组油菜株高比CK提高76.84%,含油量提高2.9百分点,单株产量比对照提高37.7%;25%甲维·氯虫苯EC 150 g/hm^2处理对茎象甲成虫防治效果最高,达85.45%,为害株率比CK降低75.8%,其次为20%氯虫苯甲酰胺SC 150 g/hm^2,防治效果达到80.21%,两种药剂处理可使油菜农艺性状株高、分枝部位、一次分枝数、主花序长比对照显著提高,一次分枝长度则显著降低,单株产量分别比对照提高47.16%和36.76%,含油量分别提高2.63和2.93百分点;其他药剂处理对油菜茎象甲成虫防治效果在49.69%～69.23%之间,防治效果较差。

Transfer of Superior Traits from Brassica juncea into Brassica napus

Both Brassica juncea（mustard）and B.napus（rapeseed）are allotetraploid species of Brassica.Although these two species have their unique characters,they possess a common A genome and a few homeologous chromosomes between the genomes B and C,which provide the foundation for transfer of superior traits from B.juncea into worldwide cultivated B.napus.The unique characters of B.juncea were summarized,breeding procedure for introgression of superior traits from B.juncea into B.napus by the interspecific crossing proposed,and some recently developed rapeseed germplasm lines with novel traits such as yellow seed and super oil content,restorer of fertility for pol CMS,extreme early maturity,high oleic acid content and short-staure plant briefly introduced in this paper.

Analysis of Correlation between Yield and Quality Traits of Quality Hybrid Rapeseed

[Objective] This study aimed to investigate the correlation between yield and quality traits of rape. [Method] Taking ＂Sanbei 98＂ and ＂Youyan 599＂ as ex- periment materials, correlation between yield and quality traits of Brassica napus L. cultivars was explored by orthogonal rotation method. [Result] The results showed that： 1 In both the two varieties-Sanbei98 and Youyan599, erucic acid content had the largest coefficient of variation, but its average content was lower than 2% in both the two varieties （0.90% in Sanbei98 and 1.24% in Youyan599）, and the palmitic acid content had the smallest coefficient of variation. 2 In terms of the dif- ferences in quality traits at different yield levels, only the mean of eicosenoic acid content revealed significant difference in Sanbei98, and only the mean of seed-pro- tein content revealed significant difference in Youyan599, and there was no signifi- cant difference in any combined quality traits in both the two varieties. 3 The yield was negatively correlated with the erucic acid content or oil content, and posi- tively correlated with the content of seed-protein, linoleic acid, or linolenic acid, and the coefficient of correlation between the yield and either of the contents of glucosi- nolates, oleic acid, palmitic acid, stearic acid, and eicosenoic acid was smaller. ~, when the yield of a variety increased considerably, there was a certain decreasing trend in erucic acid content, oil content, the total amount of erucic chain fatty acids （El ＆ Er）, while there was an increasing trend in seed-protein content, linoleic acid content, linolenic acid content, saturated fatty acids （SFA）, the total amount of fat and protein （P ＆ F）, unsaturation index （IUFA）, unsaturated fatty acids （UFA）, the total amount of 18 carbon fatty acids （18-C FA）, unsaturated fatty acids [UFA/（Ei ＆ Er） ], and the sum of oleic acid and linoleic acid （OI ＆ Li）. 5 When the seed-pro- tein content is increased, the quality of rape oil cake is also improved; when the unsaturated index is increased, the oil stability is decreased. The increase in the total amount of unsaturated fatty acids, oleic acid and linoleic acid helps to increase in the total amount of fatty acids absorbed by human bodies. [Conclusion] This study provides a theoretical foundation for the cultivation of high-yielding and top- quality hybrid rape cultivars.

Analysis of Yield and Disease Resistance Traits of New Winter Rapeseed Varieties over the Past Twenty Years in China

Based on the results of the national regional trail for winter rapeseed in four groups,including the upper reaches,middle reaches and lower reaches of Yangtze River and Huang-Huai region in the past twenty years,new varieties of winter rapeseed showed upward trend in average yield,the yield level in Huang-huai group was higher than other groups.The changes of average effective pods per plant were not significant in any group,but the number of grain per pod and 1 000-grain weight showed increase trend.However,the increment of grains per pod in three Yangtze River groups was higher than that in Huang-Huai River group,while the increment of 1 000-grain weight was just opposite.The incidence rate of Sclerotinia sclerotiorum and viral disease in new varieties of winter rapeseed obviously decreased,and the incidence rate of S.sclerotiorum decreased lower than 5%.Genetic improvement for winter rapeseed should be focus on the number of grain per pod and 1 000-grain weight in the future,and yield level of new varieties in all four groups is expected to increase.

Correlation Analysis of SPAD Value with Chlorophyll Content and Economic Yield Traits of Brassica napus L.

[Objective] The aim was to compare differences of SPAD value, chloro- phyll content, agronomic characters, economic characters and yield traits to analyze correlation of SPAD value with other indices and establish regression functions. [Method] Based on 34 Brassica napus L. varieties, SPAD value, chlorophyll content, agronomic characters, economic characters and yield traits were measured and re- gression functions were established according to correlations. [Result] SPAD value, chlorophyll content, agronomic and economic characters and yield traits all achieved significant level in differences among 34 varieties. Specifically, SPAD value was of extremely significant correlation with chlorophyll a and b, total chlorophyll and carotenoid, and the correlation from high to low was chl-b〉chl-z〉chl-a〉chl-x. SPAD value was of significantly positive correlation with total pod number per plant, plant height, seed number per pod, yield per plant and harvest yield, and of insignificant correlation with branch point height, effective branch number, pod density of main stem, and pod length. [Conclusion] It is simple and rapid to predict chlorophyll con- tent, economic characters and yields of Brassica napus L. with SPAD value and re- gression functions.

Effects of the Application of Controlled Release Nitrogen Fertilizer on Rapeseed Yield, Agronomic Characters and Soil Fertility

In order to study the effects of controlled release nitrogen fertilizer （CRNF） application on rapeseed, a simulated experiment was carried out with 3 types of paddy soils in Dongting Lake area for 4 consecutive years of applying CRNF under double rice cropping system after planting rapeseed crop in the fallow season. The effects of CRNF application on rapeseed yield, agronomic characters and soil fertility were studied in this paper. The results showed that CRNF application improved the growth of rapeseed plant and increased rapeseed yield of CRNF treatments in the purple calcareous clayed paddy soil （PCS） and alluvial loamy paddy soil （ALS） which respectively increased by 12.2% and 9.8% compared with applying urea, re- spectively. The rapeseed yield in 70% CRNF treatment obviously decreased com- pared with urea treatment. The contents of available N and organic carbon in soil increased by 25.0% and 3.2% in CRNF treatment in the ALS after rapeseed crop, respectively; and available N increased by 13.5% in the PCS. Both rapeseed yield and soil fertility in CRNF treatment and 70% CRNF treatment were lower than those in CK treatment in the reddish yellow clayed paddy soil （RYS）. The results al- so indicated that the functions of CRNF application on rapeseed yield increase and soil nitrogen fertility improvement were very obvious in the PCS and ALS.

Molecular Markers and Agronomic Traits of a New Kind of Genic Male Sterile Material Mian 7AB-4-2 in Brassica napus L.

[ Objective] The study was to investigate the agronomic traits and breeding characteristics of genic male sterile material Mian 7AB-4- 2 in Brassica napus. [ Method] The differences in agronomic traits and polymorphisms in SSR markers, between the genic male sterile material Mian 7AB-4-2 in Brassica napus and its sisterly line Mian 7AB-4-1 were investigated by hybridization and molecular identification; and the percentage of sterile individuals of Mian 7AB-4-2 and of the hybrids with its sisterly line Mian 7AB-4-1 from test cross and back cross were also studled. [ Result] Mian 7AB-4-2 was not significantly different in agronomic traits from its sisterly line Mian 7AB-4-1 at 0.05 probability level. The per- centages of sterile individuals in the pollinated fertile Mian 7AB-4-2 plants were over 60%, and that in its sisterly line Mian 7AB-4-1 was about 25%. In test crosses with other nine sterile lines, Mian 7AB-4-1 kept the percentage of sterile individuals of sterile lines over 90%, and the percentage of sterile individuals from back cross over 80%. With regard to molecular markers, Mian 7AB-4-2 and its sisterly line Mian 7AB-4-1 were different in the band number from SSR primers a2 and E10. [ Conclusion] The results indicate that Mian 7AB-4-2 is helpful for rapeseed breeding, quickening the application of new materials in field breeding.

Analysis on Combining Ability and Heritability of the Main Agronomic Characters for JA CMS in Brassica napus L.

Fifteen combinations crossed by five JA cytoplasmic male sterile lines （A1, A2, A3, A4, A5） and three restoring lines （R1, R2, R3） were selected to analyze the combining ability and heritability of nine main agronomic characters of Brassica na-pus L. to definite the application potential of these parent materials. The result showed that （i） the general combining ability （GCA） of male parents was R3＆gt;R2＆gt;R1 and that of female parents was A4＆gt;A1＆gt;A2＆gt;A5＆gt;A3; （i ） the special combining ability （SCA） of A2＆#215;R3 in plant height, number of branches, number of pods per plant and yield per plant was the best. The yield per plant of A2＆#215;R3, A1＆#215;R1 and A2＆#215;R1 ranked the first three places in the 15 combinations; （i i） the broad heritability of yield per plant was the highest, and that of the height of branches was the lowest. The com-prehensive characters of R3, A2 and A4 were better, which could be used to create new materials; （iv） good offspring were more likely to be chosen from the combina-tion with higher parental GCA, so the GCA and SCA should be considered com-prehensively when choosing parent and determining the optimal combinations.

Effect of Cultivation Conditionss on Quality Parameters of High Grade Hybrid Rape of Brassica napus L.

[Objective] This study aimed to investigate the combined effects of sowing date, plant density, nitrogenous fertilizer, phosphorus fertilizer and potassium fertilizer on quality parameters of high grade hybrid rapeseed. [Method] By using Youyan 599 and Sanbei 98 as experimental materials, quadratic orthogonal rotation combination with five factors was designed for this study. [Result] Erucic acid content was nega- tively correlated with sowing date and nitrogen fertilizer, positively correlated with plant density. Glucosinolate content was negatively correlated with sowing date, positively correlated with potash fertilizer amount. Oil content was negatively correlated with sowing date and nitrogen fertilizer amount, positively correlated with plant density and potash fertilizer amount. Protein content was positively correlated with sowing date and nitrogen fertilizer amount, negatively correlated with plant density and potash fer- tilizer amount. Oleic acid content was negatively correlated with phosphate fertilizer amount, positively correlated with nitrogen fertilizer amount. Palmitic acid was nega- tively correlated with potash fertilizer amount, positively correlated with sowing date, plant density, nitrogen fertilizer amount and phosphate fertilizer amount in Youyan 599, but negatively correlated with sowing date, plant density, nitrogen fertilizer amount and phosphate fertilizer amount in Sanbei 98. Stearic acid content was posi- tively correlated with sowing date, plant density, nitrogen fertilizer amount and phos- phate fertilizer amount. Linoleic acid was positively correlated with density and nitroge- nous fertilizer, but negatively correlated with potash fertilizer amount. Linolenic acid was positively correlated with nitrogen fertilizer amount and potash fertilizer amount. Eicosenoic acid was negatively correlated with sowing date. There were positive cor- relations and negative correlations among cultivation conditions and quality parame- ters, and the positive correlations and negative correlations could counteract each other. Expression of quality parameters for each treatment was the combined effect. Among the 50 pairs of simple correlations of five cultivation factors and ten quality parameters, 26 pairs were consistent between two varieties, 24 pairs of simple corre- lation were not. Sowing date, plant density, nitrogen fertilizer amount and phosphate fertilizer amount showed significant influence on erucic acid of two varieties, but small effect on palmitic acid. [Conclusion] The combined effect of the five cultivation factors could not fundamentally improve the quality traits of high grade hybrid rapeseed.

Canonical Correlation Analysis of Agronomic Characters of Brassica juncea in Western China

[Objective] The study aimed at exploring the relationship among the agronomic characters of B. juncea in western China, in order to provide scientific basis for the breeding of B. juncea in western China. [Method] 39 B. juncea materials from western China were used for the canonical correlation analysis, and canonical correlations between each pair of the four ecological character （containing 18 variables） were verified, including yield characters （5 variables）, caulis characters （6 variables）, branch characters （3 variables） and pod characters （3 variables）. [Result] Yield per plant of B. juncea in western China suffered a tremendous influence from effective pod number per plant while was not significantly affected by the total pod number per plant, seed number per pod and 1 000-seed weight; the most important character related with the yield character of B. juncea in western China was caulis character, followed by the branch character and pod character; yield characters, caulis characters, branch characters and pod characters of B. juncea in western China were closely correlated. [Conclusion] In order to improve the yield characters of B. juncea in western China, caulis characters should be focused on, followed by branch characters and pod characters; rapeseed varieties with high performance in total pod number per plant and effective pod number per plant should be chosen through the perspectives of effective branch number, plant height, pod number of main inflorescence, fruit stalk number of main inflorescence and other traits, while rapeseed varieties with high performance in seed number per pod and 1 000-seed weight should be chosen through the perspectives of beak length and other traits.

Effects of Nitrogen Fertilizer Management on Biological Traits and Physiological Indexes at Seedling Stage and Yield of Directly-sown Rapeseed(Brassica napus L.)

Field experiments were carried out to study the effects of different nitroge- napplication rates and application times on biological traits and physiological indexes of directly-sown rapeseed （Brassica napus L.） at the seedling stage and investigate the relationship between these biological traits or physiological indexes at the seedling stage and yield, so as to provide scientific theoretical support for high yield and efficient fertilization management in production of winter rapeseed. Field trials were conducted in Chengdu plain of Sichuan Province under rice-rapeseed rotation system during the period of 2011-2012. The nitrogen application rate trial consisted of five nitrogen levels （0, 90, 180, 270 and 360 kg/hm2） and the nitrogen application time trial included NTl（single application as base fertilized）, NT2 （bottom application ＋one time of topdressing at seedling stage） and NT3 （bottom application＋two times of topdressing at seedling stage） under the same nitrogen rate （225 kg/hm2）. The results indicated that compared with no nitrogen application （NO） treatment, the in- crease of nitrogen fertilizer is beneficial to the increase of biological traits including plant height, green leaf number, leaf area index and dry weight of rapeseed at the seedling stage, the improvement of physiological indexes including total nitrogen content, chlorophyll content and soluble protein content of functional leaves, and the reduction of soluble sugar content. Nitrogen rate was linearly correlated with various biological traits at the seedling stage and physiological indexes including total nitro- gen content, chlorophyll content and soluble sugar content in functional leaves over- a/I, but in parabolic correlation with soluble protein content. Under the same nitrogen rate, NT2 treatment exhibited biological traits remarkably or significantly higher than NT1 treatment and NT3 treatment. The nitrogen application times were linearly cor- related with the physiological indexes of functional leaves at the seedling stage. The various biological traits and physiological index of functional leaves at the seedlings stage were in quadratic function parabolic correlation with seed yield, and the corre- lation was significant （P〈0.05）. Therefore, under the rice-rapeseed rotation system in Chengdu plain, the economic rational nitrogen rate is 180-225 kg/hm2, and the mode of bottom application ＋ one time of topdressing （NT2） is suitable.

Effects of Key Agricultural Measures of Mechanized Direct Seeding Technology on Rapeseed Yield in Chengdu Plain

Mechanized direct sowing of rapeseed is a labor-saving and highly-efficient culture technique. In order to explore high-yield cultivation techniques suitable for Chengdu Plain, effects of several key agronomic measures＇, such as sowing date, density and N fertilizers, on development and yield formation were studied by strip and split plot experiment of three factors. The research showed that optimal condi- tions for direct seeding technology can be achieved provided with scientific sowing date, density and appropriate N fertilizers, and the research showed that rapeseed yield reached the peak at 320 g/m2, when sowing date was on September 3th, sow- ing density was 30 plant/m2, and nitrogen fertilizer was 27 g/m2.

Correlation Analysis on Male Sterile Lines Characters in Rapeseed(Brassica napus L.)

[Objective] This study was conducted to evaluate the associations of many characters of male sterile lines in Brassica napus L.[Method]10 recessive genetic male sterile（RGMS）lines were used as parents to cross in a half diallel cross method to produce 45 single cross hybrids.These 45 crosses and their 10 parents were evaluated at Guiyang during 2007-2008.[Result]The positive correlations of seed yield with plant height,pods per plant,days to flowering and days to maturity were significant.Their respective correlation coefficients（r）were 0.644,0.583,0.281 and 0.341.Highly significant and negative correlation was observed between seeds per pod and seed size（-0.533）.Direct path coefficients were observed for pods per plant（0.556 2）,seeds per pod（0.407 4）,1 000-seed weight（0.481 3）,and plant height（0.401 7）to seed yield.[Conclusion]Pods per plant,seeds per pod,1 000-seed weight and plant height were positive correlated with seed yield and showed high direct contributions to yield.Other characters including branches per plant,days to flowering,days to maturity and oil content had low contributions to seed yield.

Analysis of yield and quality characteristics of winter oilseed rape in China from 2001 to 2015: towards future breeding goals

The exciting outcomes of national regional trials have led to production and industrialization of China oilseed rape to a larger extent. To understand current trends of yield and quality traits of new varieties, data of national winter oilseed rape trials from 2001 to 2015 in 4 districts （upper, middle, lower Yangtze River and Huang-Huai River） was comprehensively analyzed. Results showed that average yield of new varieties of winter oilseed rape increased during the study period. In 2013, average yield of each district reached its highest level. Number of pod per plant reached its peak in 2011 and then declined rapidly in the next 4 years. Average number of seeds per pod did not signif-cantly changed in any districts. Moreover, 1,000 seeds weight increased most obviously in Huang-Huai River district. After 2007, new oilseed rape varieties encountered the dou-ble-low quality （i.e., low erucic acid and low glucosinolate）. In addition, oil content of new oilseed rape varieties increased over 15 years period and average oil content of all tested varieties during 2006-2015 was 42.96%, which was 2.38% higher than in 2005. Future breeding goals should be set to further improve yield, oil content, oil quality （such as high oleic acid and low saturated fatty acids）, achieve full mechanization of oilseed rape pro-duction process and develop ideotypes.

Genotypic variation in phosphorus acquisition from sparingly soluble P sources is related to root morphology and root exudates in Brassica napus

Genotypic variations in the adaptive response to low-phosphorus （P） stress and P-uptake efficiency have been widely reported in many crops. We conducted a pot experiment to evaluate the P-acquisition ability of two rapeseed （Brassica napus） geno- types supplied with two sparingly soluble sources of P, A1-P and Fe-P. Then, the root morphology, proton concentrations, and carboxylate content were investigated in a solution experiment to examine the genotypic difference in P-acquisition efficiency. Both genotypes produced greater biomass and accumulated more P when supplied with A1-P than when supplied with Fe-P. The P-efficient genotype 102 showed a significantly greater ability to deplete sparingly soluble P from the rhizosphere soil be- cause of its greater biomass and higher P uptake compared with those of the P-inefficient genotype 105. In the solution exper- iment, the P-efficient genotype under low-P conditions developed dominant root morphological traits, and it showed more in- tensive rhizosphere acidification because of greater H＋ effiux, higher H＋-ATPase activity, and greater exudation of carbox- ylates than the P-inefficient genotype. Thus, a combination of morphological and physiological mechanisms contributed to the genotypic variation in the utilization of different sparingly soluble P sources in B. napus.