Correlation of Leaf and Root Senescence During Ripening in Dry Seeded and Transplanted Rice

Dry seeding is a resource-saving rice establishment method. With an equivalent yield, dry seeded flooded rice （DSR） has been considered as a replacement for traditional transplanted flooded rice （TFR）. However, the differences in leaf and root senescence during grain filling between DSR and TFR were seldom identified. In this study, the root length, root tip number and leaf senescence of rice varieties Huanghuazhan and Yangliangyou 6 during ripening were compared between DSR and TFR. Results showed that top three leaves in DSR had the characteristics of relatively lower SPAD value, lower N content and premature leaf senescence. In addition, both the total root length and total root tip number of DSR were significantly lower than those of TFR. In conclusion, premature and quick leaf senescence was related with inadequate root length and root tip number during ripening, which might result from the deficiency of nitrogen supply in DSR. Techniques on improving leaf nitrogen status and delaying the leaf senescence during grain-filling in DSR should be developed in future researches.

Prevention Effects of Pyrazosulfuron-ethyl·Quinclorac 50% WP on Stem and Leaf of Dry Direct Seeded Rice

[Objective] The aim was to explore the prevention effects of pyrazosul-furon-ethyl·quinclorac 50% WP on stem and leaf of dry direct seeded rice. [Method] Totaling 7 drug doses were set in the test and the effects were observed 5, 10, 15 and 30 d after drug application, with the remained weeds surveyed 15 and 30 d after drug application. [Result] The test showed pyrazosulfuron-ethyl·quinclorac 50%WP was safe to rice as treatment agent of stem and leaf, and rice yield increased dramatical y, with the growth rate in 2.1%-49.3%. After the drug application, the prevention effects on Echinochloa crusgal i, Ludwimlia prostrata, Monochoria vamli-nalis, and Zong grass were 92.2%, 96.6%, 93.5%, and 94.8%, and the effects on fresh weight were 94.8%, 97.1%, 93.3% and 94.9%, respectively. [Conclusion] Pyra-zosulfuron-ethyl·quinclorac 50% WP can be taken as treatment agents of stem and leaf of dry direct seeded rice.

Effect of Seed Coat on Drying Kinetics of Kidney Bean Seed

Kidney bean seed was dried in a laboratory scale fixed bed. The effect of seed coat on drying dynamic characteristics and the changes of seed coat structure were investigated. A mathematical model was established to simulate the drying process and determine the moisture diffusivity. Numerical results agree well with the experimental data. The average moisture diffusivity of the seed with separated coat is 1.67 times larger than that of the seed with coat, and the moisture diffusivity of seed cotyledon is 3.2 times larger than that of the seed coat. It is proved that the seed coat is the most main resistance of mass transfer and is also one of the key points of the optimization of heat and mass transfer for seed drying.

Prediction of Canola Seed Longevity in the Drying Process

The probit analysis has been an important tool to predict seed longevity during storage and has been applied for seed drying simulation. Sealed aluminum pouches containing approximately 50 g of canola seed at moisture range of 7% to 21% of water content web basis （%） were conditioned in water-bath at 50, 60 and 70℃ to obtain the model to evaluate the reduction of canola seed germination. This model was included in the drying simulation program and the estimated germination was compared to the experimental values of germination during drying to validate the model. Canola seeds at 21% of moisture content and germination of 93% were dried at 51℃ and 61 ℃, and the model represented significantly the drying experiments. The aim of this study was to propose a germination model to evaluate the quality of canola seeds during the drying process and to offer the seed producers an important tool to control the drying process. The experimental data validated the objectives of the proposed drying model, optimizing the process at given conditions, managing the energy consumption, according to the minimum germination or maximum moisture content limitation for seed storage. For 51℃, the drying time for canola seed would be about 6 h to maintain germination above 90% and for 61℃, 4 h of drying time maintained germination up to 89%.

Chemical Weeding in Dry Direct Seeding Fields of Single Cropping Middlelate Rice

Chemical weeding in dry direct seeding fields of single cropping middle-late rice was studied in Huida vegetable farm of Huizhou City in 2012. The main treatment was herbicide（ pretilachlor ＋ bensulfuron-methyl,Yangguo and butachlor）,and the sub-treatment was application method（ soil treatments,seedling treatment and integrated treatment）. The results showed that 80 g pretilachlor ＋ bensulfuron-methyl（ 36% pretilachlor ＋ 4% bensulfuron-methyl） diluted with 50 kg water could be sprayed or 200 g Yangguo（ 23. 9% butachlor ＋ 1. 1% bensulfuron-methyl） mixed with 15 kg sandy soil could be broadcasted per 667 m2 on the sowing day or the second day under moist condition of soil,which could effectively control weeds in dry direct seeding fields of single cropping middle-late rice.

EFFECTS OF SEEDING DENSITY AND BASIC MANURE ON THE GROWTH OF DRY NURSERY SEEDLINGS IN LATE DOUBLE CROPPING RICE IN SOUTH CHINA

During the period of dry nursery seedling raising of late double cropping indica rice in South China, both chemical fertilizer and farmyard manure did not show obvious effect on the growth of shoot and root in young seedlings at 4-leaf stage （18-day-old seedling）, but had significant effects on root growth in old seedlings with 6-7 leaves （27-day-old seedling） at suitable seeding densities (65-125g m-2). There were satistically significant differences （at 0.01 or 0.05 levels）between treatments in root number and rooting ability of root-pruned seedlings.

Experimental Study of Drying Process of COLZA Seeds in Fluidized Bed Dryer by Statistical Methods

In this study the effect of initial parameters such as inlet gas temperature, initial particles temperature and gas velocity on temperature changes of solid particles and outlet gas temperature in a fluidized bed dryer was studied. For testing, an experimental setup was established. With combination of air and Colza seeds belonging to D groups of the Geldart classification (Geldart, 1986) fluidization regime was carried out. With five test series with maintaining the inlet gas temperature, solid particle temperature and outlet gas temperature during time were carefully measured. To analyze these data by using regression analysis to predict solid particle and outlet gas temperature, 2 correlations on initial pa-rameters were presented. The result has shown that temperature gradients in the beginning of fluidization, is very high and therefore the exponential functions in the regression model is used to predict the temperature changes.

玉米种子真空冷冻干燥微观实验研究及模型分析

目的 探究真空冷冻干燥技术对玉米种子的影响。方法 基于光学显微镜成像及真空冷冻干燥技术探究各冻干条件(冻结终温、升华干燥温度、解析干燥温度)对玉米种子细胞微观结构的影响。对比分析细胞形态学参数(当量直径、周长、面积、圆度)和含水率的变化规律,建立真空冷冻干燥条件与细胞形态学参数变化率之间关联的数学拟合模型。结果 细胞形态学参数变化率和含水率与冻结终温呈负相关趋势,随升华干燥和解析干燥温度的升高呈现先减少后增大的趋势,且升华干燥温度对玉米种子形态学参数变化率影响最大。在冻结终温为-25℃、升华干燥温度为5℃、解析干燥温度为40℃下,含水率(12.81%)最低。在细胞的当量直径(9.2%)、周长(8.4%)、面积(17.68%)的变化率最小且圆度(1.78%)小于4%时,干燥效果最好。采用二次多项式模型,决定系数R2均接近于1,FSSE和FRMSE均接近0。结论 该数学模型能较好地描述各真空冷冻干燥条件对玉米种子细胞形态学参数的影响,可在一定范围内对玉米米种子真空冷冻干燥后的品质进行控制。

Production of Cocoa Butter Replacer by Dry Fractionation, Partial Hydrogenation, Chemical and Enzymatic Interesterification of Tea Seed Oil

Production of cocoa butter replacer (CBR) from tea seed oil through common modification methods of oils (dry fractionation, partial hydrogenation, chemical and enzymatic interesterification) was evaluated. Some physico-chemical properties (iodine, saponification, acid and peroxide values) and fatty acid composition (FAC) of modified samples were analyzed and compared with a reference cocoa butter (CB). Solid and liquid fractions for large amounts of unsaturated fatty acids (approx. 80%) and thereby lower iodine values (81 - 85 gI2/100g) than that of CB (37% and 34 gI2/100 g, respectively), are not suitable as CBR. Among all ratios of chemically and enzaymatically interesterified oil blends (20%, 25% and 30% of hydrogenated tea seed oil with 80%, 75% and 70% of tea seed oil/liquid fraction/solid fraction), the samples with ratio of 30:70 from both chemical and enzymatic interesterification had FAC and iodine value closer to that of CB. A comparision between chemically and enzymatically interesterified samples (CISs and EISs, respectively), in terms of solid fat content (SFC) indicated that although the SFC values in EIS were much lower than that of CB, but the thermal behavior of this sample is comprable to CB at 20℃- 30℃ (sharp melting point of CB).

薯—稻轮作模式下播种密度对旱直播水稻产量的影响

【目的】探明高地力条件下旱直播水稻播种密度对群体质量和产量的影响。【方法】在云南省冬马铃薯—水稻(以下简称“薯—稻”)轮作高地力土壤上进行田间试验,以超级杂交籼稻F优498为供试品种,设置行穴距30 cm×13 cm(CK)、30 cm×11 cm(D1)、30 cm×15 cm(D2)、30 cm×17 cm(D3)和30 cm×19 cm(D4)共5种播种密度,比较不同密度对出苗质量、茎蘖动态、叶面积指数(leaf area index,LAI)、干物质积累转运特征以及产量及其构成因素的影响。【结果】随着播种密度的减小,有效穗数逐渐减少,单穴茎蘖数逐渐增加,每穗粒数显著增加,使总颖花量维持在4.4×10^(8)/hm^(2)以上。不同播种密度在维持适宜LAI的同时,随着播种密度的减小,齐穗后干物质积累量和积累率增加,提高了收获指数,从而使产量保持在较高水平(12.0 t/hm^(2)以上)。【结论】在薯—稻轮作模式下,将旱直播水稻播种密度调减至30 cm×19 cm,有利于齐穗后干物质的积累,增加每穗粒数,实现产量的稳定高效,并具有节本增效的作用。

真空冷冻干燥升华温度对玉米种子品质的影响

本文采用真空冷冻干燥机对玉米种子进行冷冻干燥处理,研究不同升华温度(3℃、5℃、7℃、9℃)条件下其物性指标(含水率、容重、出碴率、颗粒度指数、裂纹率、最大力、最大力点变形)和活性指标(发芽率、呼吸强度、相对导电率)的变化规律。研究结果表明:玉米种子的含水率、容重、出碴率、最大力、最大力点变形随升华温度升高先降低后升高,颗粒度指数随升华温度升高先增大后减小,裂纹率、相对电导率随升华温度升高先升高后降低。不同升华温度的玉米种子活性都有所下降,发芽率也都有所下降。在升华温度5℃下玉米种子呼吸强度最小,最适宜储存。

播种量对滨海稻区水稻机械旱直播产量、米质及经济效益的影响

为了完善滨海稻区水稻机械旱直播稻高产栽培技术体系,保证产量米质同时尽量降低农业成本、降低劳动强度,提高农业生产效率、经济效益,为直播稻未来在滨海稻区发展提供理论依据。采用田间对比试验方法,研究了不同播种量对滨海稻区水稻机械旱直播产量、米质及经济效益的影响,探索滨海稻区水稻机械旱直播最佳播种量。结果表明,播种量为97.5 kg/hm^(2)机械旱直播产量最高,加工品质较好,但稻米营养品质及食味值略低于播种量为120 kg/hm^(2);水稻机械旱直播比机插秧分别减产2.13 t/hm^(2)、1.76 t/hm^(2)、2.05 t/hm^(2),但效益比机插秧分别增加了0.144万元/hm^(2)、0.218万元/hm^(2)、0.118万元/hm^(2),处理2比处理1、3分别增加0.074万元/hm^(2)、0.100万元/hm^(2)。

优质杂交稻宓香优1902直播旱种表现及栽培技术

水稻旱种是近年为适应农业生态条件而发展出的一种新兴的节水栽培技术,具有省工、节本、增效的明显优势。总结了宓香优1902在永春县旱种的产量、生育特性和农艺性状表现,并提出了相应的栽培技术措施。

Effect of Moisture Content on Melilotus suaveolens Seed Quality During Ultra-drying Storage

In order to enhance the seed storability and supply high-quality seeds for vegetation restoration in the arid and semi-arid regions in Northwest China,the effects of ultra-drying and accelerated aging on the physiological characterstics of Melilotus suaveolens seeds were studied.Melilotus suaveolens seeds were dried in a desiccator containing silica gel to 80,53,42,33,23 and 16 g·kg-1 of moisture contents（MC）,respectively.The parameters of the seed quality including germination energy（GE）,germination percentage（GP）,relative conductivity（RC）,dehydrogenase activity（DA） and α-amylase activity（AA） were determined after ultra-drying and accelerated aging.The results showed that ultra-dried seeds with 42 g·kg-1 of MC showed the minimum changes of GE and GP before and after seed aging.Moreover,ultra-dry seeds with 42 g·kg-1 of MC showed higher DA and AA,and lower RC than non-ultra-drying seeds.Therefore,ultra-drying to 42 g·kg-1 of MC was helpful for M.suaveolens seed storage.

单粒精播对花生干物质累积及根冠结构的影响

为明确花生单粒精播增产机理,大田条件下,以花育22为供试花生品种,以双粒穴播(DS)为对照,研究了单粒精播(SS)对花生干物质积累、叶面积系数、冠层结构和根系特征的影响。结果表明,花生生育前期单株和群体干物质重单粒精播和双粒穴播差异不显著,而生育中后期显著高于双粒穴播,结荚期叶面积系数单粒精播显著高于双粒穴播。从结荚期不同冠层结构来看,冠层上、中、下层叶面积系数单粒精播分别比双粒穴播高23.03%、9.34%、86.43%,单株和群体冠层叶片和茎干重单粒精播均显著高于双粒穴播,从冠层不同部位叶片和茎干重占总干重的比例来看,单粒精播冠层下部叶片和茎干重比例高;单株和群体总根干重、根长、根表面积和根体积高于双粒穴播,且中下层根系占比高。相关性分析结果表明,根干重与中下层的叶片干重、下层的茎干重呈显著正相关。综上所述,与双粒播相比,单粒精播花生植株冠层中下部发育健壮且根系大分布深是其增产的重要原因。单粒精播促根扩冠,是花生节本增产的一种有效途径。

Analysis of QTL for Seed Dormancy and Their Response to Dry Heat Treatment in Rice (Oryza sativa L.)

Quantitative trait loci (QTL) controlling seed dormancy in rice were identified usingrecombinant inbred lines (RILs) population derived from the cross between a japonicavariety Kinmaze and an indica variety DV85. Seeds of two parental cultivars and each RILwere harvested in 35d after heading. The germination percentage of these seeds at 30℃for 7 days were measured as the degree of seed dormancy. QTL analysis was performed withWindows QTL Cartographer 1.13a program by composite interval mapping. A total of four QTLfor seed dormancy were detected on chromosome 2 (two regions), 5 and 11, respectively.Phenotypic variation explained by each QTL ranged from 8.37 to 17.40%. Responses of suchloci to a dormancy-breaking treatment with dry heat were further detected. The resultsshowed that two alleles of qDOR-2-1 and qDOR-5 from DV85 as well as the allele of qDOR-11 from Kinmaze increased the seed dormancy, which seemed to be easily broken by dry heattreatment. Such loci of seed dormancy may be applied to rice genetic improvement. Theallele of qDOR-2-2 from DV85 increased the seed dormancy, which could not be broken bydry heat treatment.

不同氮素水平对旱直播粳稻产量和氮素利用率的影响

采用大田小区试验,分析不同施氮水平旱直播湿润管理下粳稻不同生育时期干物质和氮素积累、转运的差异。结果表明,增施氮肥显著提高茎、叶、穗中干物质和氮积累水平以及旱直播湿润管理下粳稻的产量,T3处理产量最高,为8660.63 kg/hm^(2)。不同施氮水平下氮素的积累及物质转运对籽粒的贡献率随施氮量增加呈上升的趋势,随着氮素水平的提高氮素吸收利用效率呈上升趋势。相关性分析表明,齐穗期和成熟期茎、叶、穗氮积累量与旱直播粳稻产量均呈极显著正相关。旱直播粳稻产量与播种-分蘖-齐穗期的茎叶氮积累速率呈显著正相关。旱直播粳稻产量与齐穗-成熟期茎的氮转运量呈显著正相关,与齐穗-成熟期的叶的氮转运量呈极显著正相关。总体上,T3处理能够提高旱直播湿润管理下的结实率,增加穗数、穗粒数,有利于促进营养器官氮素积累并向籽粒转运,提高氮肥利用效率并提升产量,是适宜吉林省中部地区旱直播湿润管理粳稻的施氮水平。

A Method for Rapid Salt-extraction of High-quality Genomic DNA from Plant Seeds

[Objective] This study aimed to explore an effective method for rapid salt- extraction of high-quality genomic DNA from dried seeds of plants. [Method] Seeds of seven varieties of crops were ground into powder. A hundred milligrams of seed powder was added to extracting solution for high salt-extraction of genomic DNA. The yield and quality of extracted DNA were determined by using ultramicro UV/Vis spectrophotometer detection method, PCR and restriction enzyme digestion. [Result] About 619.67-1 811.21 ng of genomic DNA was extracted from per 100 mg of dried seed powder of seven varieties of conventional crops. A260/A280 ratios of the obtained DNA solution all ranged from 1.87 to 2.07, the purity and quality of PCR were suitable for PCR and restriction enzyme digestion. Clear target bands of specific endogenous gene fragments of seven varieties of crops were amplified by PCR, and the obtained DNA could be fully digested with EcoRV and Hindlll.[Conclusion] This method could be used for rapid extraction of high-quality genomic DNA from dried seeds.

Relations Between Photosynthetic Parameters and Seed Yields of Adzuki Bean Cultivars (Vigna angularis)

The study comparatively examined the leaf photosynthetic capacities of different adzuki bean cultivars, high-yield 2000-75 and Jihong 9218, and low-yield Hongbao 1 and Wanxuan 1 from flowering to ripening. It showed that after flowering, the leaves of the cultivars gradually aged, the leaf chlorophyll （Chl.）, soluble protein （SP） contents, net photosynthetic rates （Pn）, transpiration rates （Tr） and stomatal conductance （G） of the cultivars tended to decline, but the leaf intercellular CO2 concentration （Ci） of the cultivars tended to rise. The leaf photosynthetic capacities of the cultivars decreased gradually from the lower to the upper nodes. The dry seed yields of the cultivars were positively correlated with their leaf Chl., SP, Pn, and Tr and Gs, and negatively associated with their leaf Ci. At the late growth stages, the high-yield cultivars maintained higher leaf Chl. contents, SP contents, Pn, Tr, and Gs than the low-yield cultivars, indicating that leaf photosynthetic capacity was one of important yield-affecting factors of adzuki bean. Therefore, it was important for a crop at the crucial stage of yield formation to maintain a high leaf chlorophyll content and a high leaf photosynthetic capacity and delay leaf aging.

超干处理对菜豆种子活力及生理生化活性的影响

本研究旨在应用硅胶干燥的方法对菜豆进行超干处理,分析其主要生理活性相关指标,以期为菜豆种子的长期储藏提供科学依据和实践参考。超干处理后,应用考马斯亮蓝G-250染色法、TTC法、硫代巴比妥酸(TBA)法等测定蛋白质含量、脱氢酶(ADH)含量等指标。结果表明‘将军’含水量在6.95%时,种子活力及生理指标均高于对照,而抗氧化酶的活性显著低于对照;‘紫冠’含水量在6.89%时,各项生理指标均高于对照,O2-含量下降;‘热那亚’含水量在6.15%时,发芽率最高,蛋白含量、ADH活性明显上升,O2-含量、MDA不显著。这表明适度超干处理对‘将军’种子影响较大,对‘紫冠’、和‘热那亚’影响较小或者没有影响。通过试验结果可知,超干处理对于保存菜豆种子是可行的,为菜豆种子的长期储藏奠定下基础。