丸化剂对水稻种子出苗和秧苗生长的影响

以早稻品种金优974、湘早籼31号和晚稻品种新香优80、湘早籼10号为材料,比较研究了自研的丸化剂与进口种衣剂对水稻萌发、出苗、秧苗素质、苗期抗病虫能力的效应.结果表明,用丸化种衣剂包衣有利于种子发芽和出苗,提高秧苗综合素质.其中,成秧率提高6.8%～9.4%,秧苗根系活力提高7.1%～32.4%,病虫害防治效果分别达到95.7%～98.5%和77.5%～90.35%.     

甘蓝型黄籽油菜粒色的遗传分析

采用MINQUE(1)统计方法,以7个不同遗传来源的甘蓝型黄籽品系为材料配制完全双列杂交,用ADM和ADAA模型对粒色进行遗传分析.结果表明,粒色主要受加性和加×加上位性效应控制,母体效应和环境对粒色的影响也很明显.用y1、y2、y3作杂交育种亲本,较易获得黄籽度较高的后代,亲本选配以y1×y2、y1×y3、y2×y6组合粒色最好.     

Detecting ALS and ACCase herbicide tolerant accession of Echinochloa oryzoides (Ard.) Fritsch. in rice (Oryza sativa L.) fields

Inconsistent control of Echinochloa oryzoides has been reported repeatedly by farmers in the major rice growing area of Turkey. Greenhouse studies confirmed the existence of cross and multiple herbicide tolerance of E. oryzoides accessions including acetolactate synthase (penoxsulam, bispyribac-sodium) and acetyl CoA carboxylase (cyhalofob-butyl) inhibiting herbicides. Comparison of 95% lower confidence intervals of ED₉₀ derived from log-logistic dose–response curves, and twice the recommended field rates of the herbicides showed some, but not distinct separation of susceptible and tolerant accessions. We used a novel method to separate heterogeneous data without a priori knowledge of grouping into more than one group. On the basis of the distribution of ED₉₀ it was possible to identify two distinct groups of the 172 accessions tested, 78% were not controlled by ALS inhibitors (penoxsulam, and bispyribac-sodium) at recommended field rates; and 38% were not controlled by the ACCase Inhibitor (cyhalofob-butyl) at twice the field rates. The effective response level of ED₉₀ resulted in 64 and 14 tolerant accessions to ALS and ACCase, respectively. Fourteen accessions showed multiple resistances to ALS and ACCase Inhibitors.Some of the accessions were strongly tolerant to both herbicide modes of action and had 100% survival even at 6 times the recommended rates. Most of these tolerant accessions were from Marmara region, predominantly in Edirne and Balıkesir, which are the regions without any crop rotation.     

Lack of 26 kDa globulin accompanies increased free amino acid content in rice (Oryza sativa L.) grains

Seed nitrogen content, protein composition and free amino acid content were determined in rice mutant lines with altered storage protein composition and their parental cultivars. The Lgc1 gene, which causes low glutelin content and high content of 13 kDa prolamin and 26 kDa globulin, did not affect grain weight, nitrogen content, or free amino acid content. The glb1 gene, which lacks the 26 kDa globulin, did not affect grain weight or nitrogen content, but in mutant lines with glb1 gene the content of the major free amino acids was significantly (1.3–1.5 times) higher than those of their parental cultivars. These results suggest that absence of 26 kDa globulin is accompanied by an accumulation of a high level of free amino acids in rice grains.     

Spatial distribution and temporal stability of crenate broomrape (Orobanche crenata Forsk) in faba bean (Vicia faba L.): A long-term study at two localities

Long-term field studies were conducted at two locations to describe the spatial distribution and temporal stability of Orobanche crenata infestation in faba bean. Spatial analysis with distance indices (SADIE) was used to provide aggregation indices for the distribution of O. crenata at different times. SADIE spatial association index was used to measure the spatial stability of O. crenata aggregation patterns through time.     

Effects of winter flooding on weedy rice (Oryza sativa L.)

Weedy rice (Oryza sativa L.), characterised by competitiveness, seed longevity, and dormancy is a troublesome weed to rice fields. Furthermore, its close botanical affinity to cultivated rice makes its control particularly difficult. However, winter flooding of rice fields can be an efficient technique to control weedy rice infestation by promoting weed seed decay, animal predation, or germination.     

Investigating early vigour in upland rice (Oryza sativa L.): Part I. Seedling growth and grain yield in competition with weeds

This paper is the first of a series that investigates whether new cropping systems with permanent raised beds (PRBs) or Flat land could be successfully used to increase farmers’ incomes from rainfed crops in Lombok in Eastern Indonesia. This paper discusses the rice phase of the cropping system. Low grain yields of dry-seeded rice (Oryza sativa) grown on Flat land on Vertisols in the rainfed region of southern Lombok, Eastern Indonesia, are probably mainly due to (a) erratic rainfall (870–1220 mm/yr), with water often limiting at sensitive growth stages, (b) consistently high temperatures (average maximum = 31 °C), and (c) low solar radiation. Farmers are therefore poor, and labour is hard and costly, as all operations are manual. Two replicated field experiments were run at Wakan (annual rainfall = 868 mm) and Kawo (1215 mm) for 3 years (2001/2002 to 2003/2004) on Vertisols in southern Lombok. Dry-seeded rice was grown in 4 treatments with or without manual tillage on (a) PRBs, 1.2 m wide, 200 mm high, separated by furrows 300 mm wide, 200 mm deep, with no rice sown in the well-graded furrows, and (b) well-graded Flat land. Excess surface water was harvested from each treatment and used for irrigation after the vegetative stage of the rice. All operations were manual. There were no differences between treatments in grain yield of rice (mean grain yield = 681 g/m²) which could be partly explained by total number of tillers/hill and mean panicle length, but not number of productive tillers/hill, plant height or weight of 1000 grains. When the data from both treatments on PRBs and from both treatments on Flat land, each year at each site were analysed, there were also no differences in grain yield of rice (g/m²). When rainfall in the wet season up to harvest was over 1000 mm (Year 2; Wakan, Kawo), or plants were water-stressed during crop establishment (Year 1; Wakan) or during grain-fill (Year 3: Kawo), there were significant differences in grain yield (g/1.5 m²) between treatments; generally the grain yield (g/1.5 m²) on PRBs with or without tillage was less than that on Flat land with or without tillage. However, when the data from both treatments on PRBs and from both treatments on Flat land, each year at each site, were analysed, the greater grain yield of dry-seeded rice on Flat land (mean yield 1 092 g/1.5 m²) than that on PRBs (mean 815 g/1.5 m²) was mainly because there were 25% more plants on Flat land. Overall when the data in the 2 outer rows and the 2 inner rows on PRBs were each combined, there was a higher number of productive tillers in the combined outer rows (mean 20.7 tillers/hill) compared with that in the combined inner rows on each PRB (mean 18.2 tillers/hill). However, there were no differences in grain yield between combined rows (mean 142 g/m row). Hence with a gap of 500 mm (the distance between the outer rows of plants on adjacent raised beds), plants did not compensate in grain yield for missing plants in furrows. This suggests that rice (a) also sown in furrows, or (b) sown in 7 rows with narrower row-spacing, or (c) sown in 6 rows with slightly wider row-spacing, and narrower gap between outer rows on adjacent beds, may further increase grain yield (g/1.5 m²) in this system of PRBs. The growth and the grain yield (y in g/m²) of rainfed rice (with rainfall on-site the only source of water for irrigation) depended mainly on the rainfall (x in mm) in the wet season up to harvest (due either to site or year) with y = 1.1x − 308; r² = 0.54; p < 0.005. However, 280 mm (i.e. 32%) of the rainfall was not directly used to produce grain (i.e. when y = 0 g/m²). Manual tillage did not affect growth and grain yield of rice (g/m²; g/1.5 m²), either on PRB or on Flat land.     

陕北黄芥黄色种皮的遗传研究

本研究采用黄芥（Brassica juncea L.）与两个不同来源的褐籽类型芥菜型油菜杂交，研究黄芥黄色种皮的遗传。结果表明：黄芥的粒色主要受母体基因型控制，褐色对黄色为显性；F2和BC1世代株间乃至株内颜色不尽一致，但黄色单株和褐色单株能够明显区分，褐色和黄色的比例分别符合3:1和1:1的分离比例，证明黄芥的粒色主要受一对主效基因控制，同时受修饰基因和环境的影响。黄籽和褐籽杂交F2代粒色与几个品质性状的相关分析，结果证明除含油量与粒色密切相关外，其脂肪酸组分的平均值与种皮颜色也有一定的相关性。     

Spatial variability in the growth of direct-seeded rainfed lowland rice (Oryza sativa L.) in northeast Thailand

Large within-field variation in rice growth often causes production loss in broadcast-seeded (BC) rainfed lowland rice. The spatial variability of direct-seeded rainfed lowland rice was evaluated in 2004, 2005, and 2007 in on-station experiments at Ubon Ratchathani, northeast Thailand, in relation to soil water content and weed infestation, by adopting semivariogram and block kriging, including comparisons among BC with harrowing (BCH; no weeding), BC with no harrowing (BCNH; no weeding), and row-seeded (RS; interrow weeding once) fields. BCH and BCNH were also compared in 11 farmers’ fields in 2006 and 2007, to assess the effect of harrowing on rice growth and weed infestation. During most of the rice growing periods, flooded and non-flooded portions existed simultaneously in the fields, with different proportions among years and among seeding methods in the on-station experiment. BCH and BCNH rice had large within-field variation in seedling density, heading date, shoot dry matter, grain yield, harvest index, panicle density, and filled spikelet per panicle, as well as in weed infestation, measured by a quick visual estimation. Many of the measured variables (except mean soil water content in RS in 2007, seedling density in BCH in 2005 and 2007, shoot dry matter in BCH and BCNH in 2007, and panicle density in BCH in 2007) were spatially dependent (i.e., data from nearby locations were most similar) by geostatistical analysis. Analysis of correlations using the 420 data sets of BCH plots in 2005 and BCH, BCNH, and RS plots in 2007 revealed a positive correlation between soil water content and grain yield and negative correlations between weed infestation and soil water content and grain yield. Compared with BCH, in 2007 BCNH had much lower grain yield because of lower soil water content after establishment and more weed infestation. BCH had higher grain yield than BCNH in weedy fields in the farmers’ fields experiment. RS with interrow weeding resulted in a smaller coefficient of variation, smaller sill value, and higher grain yield than BCH, due to less weed infestation and a higher proportion of flooded water. These results indicated that reducing the spatial variability in rice growth requires careful field preparation, such as harrowing to level the soil surface and to reduce the uneven distribution of standing water and the variability in soil water content, combined with effective crop and weed management (i.e., harrowing and row-seeding). This is the first study that examined spatial variability in the growth of direct-seeded rice as a function of soil water content and weed infestation in a rainfed lowland environment.     

Characteristics, composition and thermal stability of Acacia senegal (L.) Willd. seed oil

The chemical composition, main physicochemical properties and thermal stability of oil extracted from Acacia senegal seeds were evaluated. The oil, moisture and the ash contents of the seeds were 9.80%, 6.92% and 3.82%, respectively. Physicochemical properties of the oil were iodine value, 106.56 g/100 g of oil; saponification value, 190.23 mg KOH/g of oil; refractive index (25 °C), 1.471; unsaponifiable matter, 0.93%; acidity, 6.41% and peroxide value, 5.43 meq. O₂/kg of oil. The main fatty acids in the oil were oleic acid (43.62%) followed by linoleic acid (30.66%) and palmitic acid (11.04%). The triacylglycerols (TAGs) with equivalent carbon number ECN 44 (34.90%) were dominant, followed by TAGs ECN 46 (28.19%), TAGs ECN 42 (16.48%) and TAGs ECN 48 (11.23%). The thermal stability analysed in a normal oxidizing atmosphere showed that the oil decomposition began at 268.6 °C and ended at 618.5 °C, with two stages of decomposition at 401.5 °C and 576.3 °C. According to these results, A. senegal seed oil has physicochemical properties, fatty acids composition and thermal characteristics that may become interesting for specific applications in several segments of food and non-food industries.     

Diversity of weedy red rice (Oryza sativa L.) in Arkansas,U.S.A. in relation to weed management

Weedy rice, specifically red rice (Oryza sativa L.), is a major weed in rice which causes up to 80% yield loss and reduction of grain quality. Red rice accessions from Arkansas, U.S.A., were characterized to classify red rice accessions into certain phenotypic groups relevant to weedy rice management. The red rice accessions were 70% strawhull, 22% blackhull, 7% brownhull and <1% goldhull. Generally, blackhull red rice was the tallest (139 cm) and strawhull the shortest (133 cm) among all accessions. Blackhull red rice had more tillers (102/plant), smaller flag leaves (13 cm wide, 34 cm long), and flowered later (1225 heat units) than strawhull red rice which had 85 tillers/plant, 15 cm-wide and 34 cm-long flag leaves, and flowered after accumulating 1195 heat units. Morphological differences between accessions within each hull type were highly significant, showing great diversity within a hull color group as indicated by large ranges in traits. For example, blackhulls were 75–190 cm tall with 18–69 cm long flag leaves, 21–188 tillers and produced 40–949 g seed. Strawhulls were 46–189 cm tall with 18–66 cm flag leaf length, 16–172 tillers and produced 100–608 g seed. Some traits, such as seed production, differed widely between accessions within each hull color group such that the average seed production/accession for blackhull did not differ from that of strawhull weedy rice (196 vs. 192 g/plant). The onset of flowering among all accessions ranged from 56 to 126 d after planting. Red rice accessions formed six phenotypic clusters generally segregated by plant size or flowering time. Each morphotype would have different competitive abilities; thus, weedy rice management could be geared toward plant types. Highly competitive plant types would require intensive control measures to minimize yield losses and reduce the soil seed bank. Flowering dates impact stewardship strategies for herbicide-resistant or any genetically modified rice.     

甘蓝型油菜种子贮藏蛋白遗传距离与杂种优势关系研究

对38份不同生态区来源的甘蓝型油菜种质进行了贮藏蛋白电泳多态性分析,并对165个杂交组合农艺、品质性状表现及杂种优势与亲本贮藏蛋白距离进行相关分析,探讨了贮藏蛋白标记遗传距离辅助甘蓝型油菜农艺及品质杂种优势利用的可能性。结果表明：甘蓝型油菜种子贮藏蛋白多态性丰富;谷蛋白标记遗传距离（GDglu）、清蛋白标记遗传距离（GDalu ）与农艺、品质性状杂种后代表现及中亲优势存在不同程度的相关性,可以利这种相关性及谷蛋白标记遗传距离聚类辅助甘蓝型油菜杂交育种和品质育种的亲本选配,提高选配效率。     

Some physical properties of rough rice (Oryza Sativa L.) grain

Designing the equipment for processing, sorting, sizing and other post-harvesting equipment of agricultural products requires information about their physical properties. In this study, various physical properties of rough rice cultivars were determined at a moisture content of 10% (wet basis). In the case of Sorkheh cultivar, the average thousand grain weight, equivalent diameter, surface area, volume, sphericity, aspect ratio, true density, bulk density and porosity were 21.64 g, 3.35 mm, 31.76 mm², 20.27 mm³, 39.71%, 0.28, 1269.1 kg/m³, 544.34 kg/m³, and 56.98%, respectively. The corresponding values were 20.52 g, 3.4 mm, 32.58 mm², 21.06 mm³, 39.88%, 0.29, 1193.38 kg/m³, 471.21 kg/m³, and 60.37% for Sazandegi cultivar. For Sorkheh cultivar, the average static coefficient of friction varied from 0.2899 on glass to 0.4349 on plywood, while for Sazandegi cultivar the corresponding value varied from 0.2186 to 0.4279 on the same surfaces. Angle of repose values for Sorkheh and Sazandegi cultivars were 37.66° and 35.83°, respectively. Linear model for describing the mass of rough rice grain was investigated. Mass was estimated with single variable of kernel length with a determination coefficient as 0.862 for Sorkheh cultivar whereas for Sazandegi cultivar was as 0.860.     

QTL analysis of cold tolerance at seedling stage in rice (Oryza sativa L.) using recombination inbred lines

Cold tolerance at seedling stage of rice (Oryza sativa L.) is a favorable trait for the stable establishment in temperate and high-elevation areas. In the present study, 71 recombinant inbred lines (RIL) derived from the cross of Asominori (Japonica) and IR24 (Indica) were used to identify quantitative trait loci (QTL) affecting cold tolerance at seedling stage. The putative QTL was further confirmed using some chromosome segment substitution lines (CSSLs), in which IR24 was used as the donor parent and Asominori as the recurrent parent. The average seedling mortality was used as cold tolerance after cold treatment with 6 °C for 7 days and recovery culture with 25 °C for 4 days at three-leaf seedling stage. Three QTL affecting cold tolerance at seedling stage were detected on chromosomes 1, 5 and 6 with LOD scores ranging from 2.2 to 4.1 using composite interval mapping (CIM). Among them, qSCT-1 located in the region of XNpb87-2-C955 on chromosome 1 was a major QTL which explained 24.51% of total phenotypic variance and favorable allele came from japonica parent, Asominori. In addition, IR24 alleles at the other two loci (qSCT-5 and qSCT-6) increased cold tolerance. And these three QTL were confirmed by four lines from the IR24 CSSLs. Transferring favorable allele from japonica variety to indica background or pyramiding different QTL identified from indica is an effective way to improve cold tolerance of rice.     

Microbial populations associated with the retting of melon pods ( Colocynthis citrullus L.) during seed recovery

The traditional process for the retting of melon pulp and microbiological characteristics in the recovery of melon seeds ( Colocynthis citrullus L.) were investigated. Melon pods were sliced open and exposed for seven days. The pulp underwent a natural fermentation that was characterised by the growth of microorganisms to 108–1010 cfu/g. The pH fluctuated between 4.8 and 5.1 with a lactic acid content of 0.72%. Bacillus subtilis, B. polymyxa, Lactobacillus fermentum, L. brevis and Streptococcus faecalis were the predominant microorganisms but, significant contributions were made by Staphylococcus saprophyticus and Enterobacter cloacae. Penicillium, Aspergillus and Rhizopus species including the yeasts, Sacharomyces cerevisiae Candida krusei and Deboromyces hansenii were isolated from the fermentation. Growth of microorganisms was completely inhibited in antibiotic-treated samples indicating that the melon pods were the main source of microorganisms for the fermentation.     

Dynamical partition of photosynthates in tillers of rice (Oryza sativa L.) during late growth period and its correlation with feeding value of rice straw at harvest

This study was to investigate the dynamical partition of photosynthates in panicle-removed tillers of rice (Oryza sativa L.) during late growth period and its correlation with the feeding value of rice straw at harvest. Four rice cultivars (Liangyou 108, Huaidao 6, Nanjing 43, Nanjing 44) were cultivated in Nanjing under the same management of Jiangsu area, and were sampled from weeks 1 to 5 after anthesis and at harvest in 2008, 2009 and 2010. Then, the content of nonstructural carbohydrates (NSC), hemicellulose, and acid detergent fiber (exclusive of residual ash, ADFom) in tillers were determined. The crude protein (CP) content in tillers at harvest was assayed in 2009 and 2010. Freehand sections of the fourth internode of main culm were made to visualize the starch particles in parenchyma cells in week 1, 3 and 5 after anthesis in 2010. The results showed that the content of NSC decreased sharply from week 1 to 3 and then increased to week 5 after anthesis; hemicellulose in week 5 remained at an approximate level with that of week 1; ADFom increased slightly from week 1 to 3, and then stayed constant till week 5 after anthesis. The starch particles in parenchyma cells of stems decreased from week 1 to 3 and increased slightly till week 5 after anthesis again. The rebounding rate of NSC (NSCRR) was positively correlated with the content of NSC and CP at harvest while negatively correlated with the content of hemicellulose and ADFom at harvest.     

Identification of a GDSL-motif carboxylester hydrolase from rice bran (Oryza sativa L.)

A major esterase (designated OsEST1) showing high activity using 1-naphthyl acetate as a substrate was identified from rice bran and purified approximately 239-fold to near-homogeniety. The purified enzyme migrated as a single polypeptide band on native and SDS-polyacrylamide gels and had a molecular mass of 25 kDa under denaturing conditions. Analysis of its tryptic peptides by MALDI-TOF-MS and subsequent data mining identified a corresponding cDNA OsEST1 consisting of 714 nucleotides and encoding a 238 amino acid protein. Analysis of its primary sequence indicated that OsEST1 is a GDSL-motif carboxylester hydrolase belonging to the SGNH protein subfamily in containing the putative catalytic triad of Ser¹¹, Asp¹⁸⁷, and His¹⁹⁰. OsEST1 showed the highest catalytic activity at approximately pH 8.0–8.5 and at 45 °C with K_m and V_max values for 1-naphthyl acetate of 172 μM and 63.7 μmol/min/mg protein, respectively. However, OsEST1 showed no activity with triacylglycerol. Alignment of the primary sequence of OsEST1 and other rice GDSL-motif esterases/lipases showed that OsEST1 aligns with a specific family of plant SGNH esterases involved in response to dehydration and cuticle formation. These results suggest that OsEST1 is not a lipase but an esterase activity which has some other function in rice, especially during seed development.     

Response of the leaf photosynthetic rate to available nitrogen in erect panicle-type rice (Oryza sativa L.) cultivar,Shennong265

Increasing the yield of rice per unit area is important because of the demand from the growing human population in Asia. A group of varieties called erect panicle-type rice (EP) achieves very high yields under conditions of high nitrogen availability. Little is known, however, regarding the leaf photosynthetic capacity of EP, which may be one of the physiological causes of high yield. We analyzed the factors contributing to leaf photosynthetic rate (P_n) and leaf mesophyll anatomy of Nipponbare, Takanari, and Shennong265 (a EP type rice cultivar) varieties subjected to different nitrogen treatments. In the field experiment, P_n of Shennong265 was 33.8 μmol m^?2 s^?1 in the high-N treatment, and was higher than that of the other two cultivars because of its high leaf nitrogen content (LNC) and a large number of mesophyll cells between the small vascular bundles per unit length. In Takanari, the relatively high value of P_n (31.5 μmol m^?2 s^?1) was caused by the high stomatal conductance (g_s; .72 mol m^?2 s^?1) in the high-N treatment. In the pot experiment, the ratio of P_n/C_i to LNC, which may reflect mesophyll conductance (g_m), was 20–30% higher in Nipponbare than in Takanari or Shennong265 in the high N availability treatment. The photosynthetic performance of Shennong265 might be improved by introducing the greater ratio of P_n/C_i to LNC found in Nipponbare and greater stomatal conductance found in Takanari.     

Effect of rice establishment methods on weedy rice (Oryza sativa L.) infestation and grain yield of cultivated rice (O. sativa L.) in Sri Lanka

Weedy rice is a great threat to rice production in Sri Lanka. Selective herbicides to manage weedy rice in conventional rice cultivars are not available in Sri Lanka. In the absence of appropriate chemical control measures, cultural approaches may help to achieve effective control of weedy rice. A study was conducted in two consecutive seasons in farmers' fields at three sites (Atalla, Samanthurai, and Girithale villages) in Sri Lanka to evaluate the effect of different establishment methods (farmers' practice, random broadcast, row seeding, seedling broadcast, and transplanted rice) on weedy rice infestation and rice yield. The farmers' practice had a higher number of weedy rice panicles (60–80 m⁻²) than the random broadcast (39–48 panicles m⁻²), seedling broadcast (3–15 panicles m⁻²), and transplanted rice (1.3–3.0 panicles m⁻²) methods. The use of clean rice seeds in the random broadcast method reduced weedy rice seed production by 29–41% compared with the farmers' practice (0.6–2.0 t ha⁻¹). Compared with the farmers' practice, the seedling broadcast method reduced weedy rice seed production by 71–87% and transplanted rice by 95–98%; and increased rice yield by 27–49% (7.5–9.1 t ha⁻¹). At all three sites, the farmers' practice resulted in the lowest grain yield (5.1–6.7 t ha⁻¹). Compared with the farmers' practice, the random broadcast and row seeding methods increased rice yield by up to 21% and 31%, respectively. The findings suggest that the use of clean rice seeds, the use of a row-seeded crop, and the adoption of different rice planting methods may help to suppress the spread of weedy rice.