Study on High-yielding Seed Production Technologies of Japonica Hybrid Rice

[Objective] This study aimed to investigate the high-yielding seed production technologies of japonica hybrid rice. [Method] Key technologies affecting the seed production of japonica hybrid rice were investigated based on manual transplanting experiment, mechanical transplanting experiment, paclobutrazol chemical control experiment, leaf-clipping experiment, gibberellic acid treatment experiment and experiment of different row ratios of male and female parents. [Result] The duration from seeding to heading was significantly shortened with sowing date postponing. The sowing date of mechanical-transplanting parents should be 3 -4 d earlier than that of manual-transplanting parents. Spraying paclobutrazol had significantly control effect on plant height of rice seedlings, and the spraying dose should be determined based on the sensitivities of different parents to paclobutrazol, with an appropriate range of 600-900 g/hm2 . Leaf clipping had certain improving effect on the seed-setting rate. The appropriate spraying dose of gibberellin for japonica hybrid rice was 75-90 g/hm2 . The yield would be relatively high when row ratio of male and female parent was 6∶2. [Conclusion] This study laid the foundation for improving the yield of produced japonica hybrid rice seeds.

High-yielding Seed Production Techniques and Characteristics of Hybrid Rice Yanliangyou 888

According to seed production of Yanliangyou 888, a two-line hybrid rice variety, the research reviewed seed production characters, as follows： to improve outcrossing rate and spike size provided sufficient spikes of female/male parents. The seed production techniques include scientific arrangement of seeding interval, cultivating strong multi-tiller seedlings, scientific arrangement of row ratio of inter- cropping with adequate basic seedlings, scientific water and fertilizer management, improving outcrossing rate by synthesis measures, disease/insect control, and rein- forcing production management.

High-yielding Seed Production Techniques of Disease-resistant and High-quality Hybrid Rice Sterile Line Rong 18A

Rong 18A, bred by Crop Research Institute, Chengdu Academy of Agri- culture and Forestry Sciences is a new blast-highly resistant and high-combining ability hybrid rice sterile line. It is currently one of the male sterile lines in Sichuan Province which combine well high grain quality and rice blast resistance. More than 20 combinations of Rong 18A have passed the national and provincial variety iden- tification. Combined with the climate conditions in Chengdu, the key points of high- yielding seed production techniques for Rong18A are analyzed and summarized in this paper.

Small auxin-up RNA gene OsSAUR33 promotes seed aging tolerance in rice

Seed aging tolerance during storage is generally an important trait for crop production, yet the role of small auxin-up RNA genes in conferring seed aging tolerance is largely unknown in rice. In this study, one small auxin-up RNA gene, OsSAUR33, was found to be involved in the regulation of seed aging tolerance in rice. The expression of OsSAUR33 was significantly induced in aged seeds compared with unaged seeds during the seed germination phase. Accordingly, the disruption of OsSAUR33 significantly reduced seed vigor compared to the wild type(WT) in response to natural storage or artificial aging treatments. The rice OsSAUR33 gene promotes the vigor of aged seeds by enhancing their reactive oxygen species(ROS) level during seed germination, and the accumulation of ROS was significantly delayed in the aged seeds of Ossaur33 mutants in comparison with WT during seed germination. Hydrogen peroxide(H_(2)O_(2)) treatments promoted the vigor of aged seeds in various rice varieties. Our results provide timely theoretical and technical insights for the trait improvement of seed aging tolerance in rice.

High-yielding Seed Production Techniques of New Hybrid Rice Combination-Chuanxiang No.2058

Chuanxiang No.2058 is a new combination of three-line late indica hybrid rice bred based on sterile line Chuanxiang 29A and restorer Qiannanhui No.2058. In order to promote its application, seed production techniques of Chuanxiang No.2058 were explored during 2009-2010. The research detailed the seed production tech- niques from selection of seed production bases, rational arrangement of sowing gap stage, seedling cultivation in different stages, scientific arrangement of male/female parents, management of fertilizer and water, adjustment of florescence, artificial pol- lination, comprehensive treatment of disease and pest damages, and timely control- ling of abnormal and poorly-qualified rice.

Identification of long InDels through whole genome resequencing to fine map qIF05-1 for seed isoflavone content in soybean(Glycine max L. Merr.)

Soybean seed isoflavones are a type of secondary metabolites that can provide health and nutrition benefits for humans. In our previous study, a stable quantitative trait locus(QTL) qIF05-1 controlling the seed isoflavone content in soybean was detected on chromosome(Chr.) 05 in a recombinant inbred line(RIL) population from a cross of Huachun 2×Wayao. In this study, the parental lines were re-sequenced using the Illumina Solexa System with deep coverage. A total of 63,099 polymorphic long insertions and deletions(InDels)(≥15 bp)were identified between the parents Huachun 2 and Wayao. The InDels were unevenly distributed on 20chromosomes of soybean, varying from 1,826 in Chr. 12 to 4,544 in Chr. 18. A total of 10,002 long InDels(15.85% of total) were located in genic regions, including 1,139 large-effect long InDels which resulted in truncated or elongated protein sequences. In the qIF05-1 region, 68 long InDels were detected between the two parents. Using a progeny recombination experiment and genotype analysis, the qIF05-1 locus was mapped into a 102.2 kb genomic region, and this region contained 12 genes. By RNA-seq data analysis, genome sequence comparison and functional validation through ectopic expression in Arabidopsis thaliana, Glyma.05G208300(described as GmEGL3), which is a basic helix-loop-helix(bHLH) transcription factor in plants, emerged as the most likely confirmed gene in qIF05-1. These long InDels can be used as a type of complementary genetic method for QTL fine mapping, and they can facilitate genetic studies and molecular-assisted selection breeding in soybean.

Effect of N Fertilization on Yield, N Absorption and Utilization of Two Species of Super High-Yielding Summer Maize

[Objective] The aim was to study on effects of N fertilizer on yield, N absorption and utilization of different cultivars of super high-yielding summer maize, in order to provide reference for reasonable N fertilization in accordance with different cultivars. [Method] Field experiment was conducted to study on effects of different N fertilizers on yield, N absorption and use efficiency of Zhengdan 958 and Xundan 20, in order to learn the effect differences at different N fertilizer levels. [Result] After N was applied, yields of the two summer maize increased significantly. Zhengdan 958 achieved the highest in yield and proceeds at 12 051.18 kg/hm2 and 1 722.40 yuan/hm2, respectively in low N level. In contrast, Xundan 20 achieved the highest at 13 166.00 kg/hm2 and 1 343.92 yuan/hm2 in the above two aspects in high N level. Compared with Zhengdan 958, Xundan 20 increased by 9.90%, 5.20% and 12.00% in N levels of 0, 240, and 450 kg/hm2, respectively. When N fertilizers were applied, protein yield of Xundan 20 was significantly higher than that of Zhengdan 958, so that higher N fertilizers contributed higher protein yield for Xundan 20. In high N level, N efficiency, N-fertilizer utilization and partial productivity of Xundan 20 were significantly higher than that of Zhengdan 958. [Conclusion] Lower N-fertilizer was suitable for Zhengdan 958 and Xundan 20 would get a good harvest if more N-fertilizers were applied. The results provided references for reasonable N fertilization.

Effects of Ratio of Row Spacing to Intrarow Spacing on Yield and Top Three Leaves of Super High-yielding Early and Late Rice

Using a split plot design, super high-yielding early rice ＆quot;Zhongjiazao 17＆quot;and ＆quot;Ganxin 203＆quot; and super high-yielding late rice ＆quot;Ganxin 688＆quot; and ＆quot;Wufengy-ouT025＆quot; were taken as materials with planting density the same at 312 000 hil s/hm2, to explore the effects of RS/IS （Ratio of row spacing to intrarow row spacing） on yield, top three leaves morphological features and its relationship of them in 2011 and 2012. The results showed that, whether early or late rice, biomass, accumula-tion and apparent utilizing rate of nitrogen were lower in RS/IS5.0 （40.0 cm ＆#215;8.0 cm） treatment, but yield of rice was higher in RS/IS2.0 （25.0 cm ＆#215;12.8 cm） treatment;grain numbers per spike of rice was more in RS/IS2.8 （30.0 cm＆#215;10.7 cm） treatment, and thousand-grain weight of rice was higher in RS/IS1.3 （20.0 cm＆#215;16.0 cm） treat-ment. For 4 varieties of early or late rice aforementioned, basal angle, opening an-gle and leaf area of 2nd leaf from top were larger in RS/IS5.0 treatment, and basal angle and opening angle were smal er in RS/IS2.0 treatment and leaf area smal er in RS/IS1.3 treatment.

Simplified High-yielding Cultivation Technology of Rice

[Objective] The aim was to select simplified high-yielding cultivation technology of rice. [Method] The research explored three methods of farmland prepara- tion, transplanting, and fertilization including shallow rotary tillage and deep ploughing, mechanical transplanting and hand transplanting, controlled-release fertilizer and quantitative fertilization in order to investigate effects of different treatment groups on rice characteristics, economic characteristics, as well as labor saving, yield increasing and profit improving. [Result] Rice increased by 596.4-809.55 kg/hm2, labor saving reached 120-135 per hm2, and profit improved in the range from 5 521.39 to 8 727.48 yuan/hm2 in the treatment groups by combinations of shallow rotary tillage, mechanical transplanting, and controlled-release fertilizer, of shallow rotary tillage, mechanical transplanting, and quantitative fertilization, and of deep ploughing, mechanical transplanting, and controlled release fertilizer. [Conclusion] The three models are of promising prospects in production.

High-yield Seed Production Techniques of Late Japonica Hybrid Rice Tongyoujing 1

The differences in growth period and seeding to heading duration of both parents of Tongyoujing 1 are 4-6 and 3-5 d, respectively. Plant height of the male parent was 6-8 cm higher than that of the female parent, and blooming time of the male parent was 30-60 min earlier than that of the female parent. The seed pro-duction technology points of Tongyoujing 1 include appropriate seeding （the differ-ence in sowing period of both parents is 3-5 d）, timely transplanting, reasonable layout （ratio of rows between both parents is 2：（6-8））, strengthening variety isolation, scientific fertilizer and water management （high fertilization for male parent and ade-quate fertilization for female parent）, reasonably regulating flowering period （to pro-mote flower synchronization）, artificial pollination （to improve outcrossing rate）, paying attention to miscel aneous plant removal and pest control and timely harvest.

Performance and High-yielding Cultural Techniques of Hunyou No.2 in Myanmar

Hunyou No. 2 is a three-line hybrid rice suitable for mechanical seed pro- duction and developed by Rice Research Institute of Anhui Academy of Agricultural Sciences. It performs well in yielding, lodging resistance, disease resistance, with a short duration of growth. Therefore, it is suitable to be grown in tropical areas and countries such as Myanmar and Indonesia. The male parent contains herbicide susceptible lethality gene and it is possible for mechanical mixed planting. The research analyzed performance of Hunyou No. 2 growth in Myanmar and the results showed that Hunyou No. 2 performed better in yield, panicle length, the number of seed per panicle, setting percentage, and thousand-seed weight than She thwe yin, as well as lodging resistance, disease resistance and quality. Some high-yielding cultivation measures have been concluded including sparsely sowing, densely planting, highlighting base fertilizers, and avoiding early water breaking.

Effects of culm carbohydrate partitioning on basal stem strength in a high-yielding rice population

Rice culm carbohydrate transport can simultaneously affect grain filling and stem lodging resistance by regulating non-structural carbohydrate(NSC) and structural carbohydrate(SC) contents. However, the relationship between carbohydrate transposition and culm strength is not well documented. Accordingly, a high-yielding hybrid rice cultivar(Y Liangyou 2) was tested under different N fertilization regimes at two locations, Taoyuan(a special high-yield eco-site), Yunnan province and Danyang(a representative eco-site of the middle and lower Yangtze), Jiangsu province, China. Significantly higher grain yield and basal stem strength were found at Taoyuan than Danyang under all N rates throughout the two-year experiment. At heading stage, soluble sugars, starch, cellulose and lignin contents of the basal culm at Taoyuan were significantly 132.0%, 73.7%, 1.2%, and 62.7% higher than those at Danyang, respectively. At 20 days after heading, soluble sugars and starch content at Taoyuan decreased significantly compared to Danyang, but lignin content remained higher. Culm carbohydrate transport to kernels at Taoyuan was significantly greater than that at Danyang, and the proportion of soluble sugars and starch was correspondingly 62.9%lower. However, the proportion of lignin and cellulose was 22.7% higher at Taoyuan than that at Danyang. Soluble sugars and starch partitioning were significantly reduced under an increased nitrogen application rate, but SC partitioning was little affected. There were significant positive correlations between basal culm bending stress and dry weight and cellulose and lignin proportions at both locations under all N rates, suggesting that the higher SC proportion at 20 days after heading was primarily responsible for culm strength.These results suggest that high-yielding rice populations with greater culm strength require both moderate NSC transport and greater SC accumulation.

Plant Ideotype at Heading for Super High-Yielding Rice in Double-Cropping System in South China

The newly released super high-yielding hybrid rice combinations, Yueza 122, Fengyou 428, Peiza 67, and the super high-yielding conventional cultivars, Guangchao 3 and Shengtai 1, were grown in both early and late seasons. The morphological characters of each population were investigated at the heading stage, and the data were analyzed by using ANOVY and other statistic methods. The plant ideal morphological characters at the heading stage were established as follows： 1 ） for the early-season cropping, 90-105 cm plant height; 11-12 tillers per plant; 35-40 em length and 2.1-2.2 cm width of flag leaf; 46-50 cm length and 1.8-2.1 cm width of the second leaf from the top （L2）; 59-64 cm length and 1.4-1.9 cm width of the third leaf from the top （L3）; 7°-14°, 18° and 200-33° for the ideal leaf angles of the flag leaf, L2 and L3, respectively; 2） for the late-season cropping, 90-100 cm plant height; 9-15 tillers per plant; 30-41 cm length and 1.8-2.0 cm width of flag leaf; 53-61 cm length and 1.3-1.8 cm width of L2; 52-58 cm length and 1.2-1.5 cm width of L3; 9°-19°, 15°-37° and 16°-49° for the ideal leaf angles of the flag leaf, L2 and L3, respectively. The main physiological characteristics of these varieties were also analyzed.

Study on Plant Morphological Traits and Production Characteristics of Super High-Yielding Soybean

Super high-yielding soybean cultivar Liaodou 14, soybean cultivars from Ohio in the United States, and the common soybean cultivars from Liaoning Province, China, with similar geographic latitudes and identical pod-bearing habits were used as the study materials for a comparison of morphological traits and production characteristics to provide a theoretical basis for the breeding of improved super high-yielding soybean cultivars. Using a randomized block design, different soybean cultivars from the same latitude were compared under conventional and unconventional treatments for their production characteristics, including morphological traits, leaf area index （LAI）, net photosynthesis rate, and dry matter accumulation. The specific characteristics of the super high-yielding soybean cultivar Liaodou 14 were analyzed. The results showed that the plant height of Liaodou 14 was significantly lower than that of the common cultivars from Liaoning, whereas the number of its main-stem nodes was higher than that of the cultivars from Ohio or Liaoning. A high pod density was observed in Liaodou 14 under conventional treatments. Under both conventional and unconventional treatments, the branch number of Liaodou 14 was markedly higher than that of the common cultivars from Liaoning, and its branch length and leaf inclination angle were significantly higher than those of common cultivars from Liaoning or Ohio. Only small changes in the leaf inclination angle were observed in Liaodou 14 treated with conventional or unconventional methods. Under each treatment, Liaodou 14 exhibited the lowest amplitude of reduction in SPAD values and net photosynthesis rates from the grain-filling to ripening stages; the cultivars from Ohio and the common cultivars from Liaoning exhibited more significant reductions. Liaodou 14 reached its peak LAI later than the other cultivars but maintained its LAI at a higher level for a longer duration. Under both conventional and unconventional treatments, Liaodou 14 produced a higher yield than the other two cultivars, with significant differences from the Ohio cultivars. In summary, super high-yielding soybean cultivars have several main features： suitable plant height, high pod density, good leaf structure with strong functionality, and slow leaf senescence at the late reproductive stage, which is conducive to the accumulation of dry matter and improved yield.

Survey on Early-bearing High-yielding Model Plantation of Camellia oleifera

[Objective] This study was conducted to screen the best variety and optimum planting density for constructing early-bearing high-yielding model plantation of Camellia oleifera. [Methed] This survey was carried out in two demonstration bases, one for investigating the relationship between different cultivated varieties with growth and production, the other for investigating the relationship between different planting densities with growth and production. [Result] For different cultivated varieties, Cenruan 2 showed tree height, ground diameter and crown product significantly higher than other two varieties, besides, the per unit area fruit yield of Cenruan 2 was also significantly higher than other two varieties. From flower bud differentiation,the best variety was Changlin 4, which showed number of differentiated flower buds significantly higher than Changlin 27, but there were no significant differences between Cenruan 2 with Changlin 4 and Changlin 27. For different planting densities, plant height and crown product at planting density of 1.5 m×2 m were significantly higher than those of other two planting densities, but from ground diam- eter, the best planting density was 1.5 m×1.0 m, with a ground diameter significantly higher than other two planting densities. From per unit area fruit yield, the best planting density was 1.5 m×2.0 m, under which early plant growth and fruit production were better. Therefore, the best planting density is 2.0 m ×3.0 m when constructing early-bearing high-yielding model plantations. For variety Cenruan 3, it＇s fruit production is high in the early pedod, and the best planting density is 1.5 m× 2.0 m or 1.0 m×1.5 m when constructing early-bearing high-yielding model plantations, and after 4-6 years when it put into production, the plants could be transplanted.

Investigation of Tree Structure Parameters of High-quality and High-yielding Y-shaped Pear Orchards

In order to study reasonable tree structure parameters of Y-shaped pear orchards in natural conditions and at management technical level of Tai'an area, the tree structure and population structure of high-quality and high-yielding Y-shaped pear orchards were investigated. The results showed that when the yield of Y-shaped 'Oshu' was 2 550 kg/667 m^2 in the early fully fruiting period, the quantity of the branches per 667 m^2 was about 54 000, and the number of short branches was the largest, accounting for 80.1% of total number of branches, followed by middle branches, long branches and developmental branches. As the yield of Y-shaped 'Qiuyue' was 2 875 kg/667 m^2 in the early fully fruiting period, the quantity of the branches per 667 m^2 was 51 000, and the number of short branches was the largest, accounting for 75.6% of total number of branches, followed by middle branches, long branches and developmental branches. When the yield of Y-shaped 'Niitaka' was 3 000 kg/667 m^2 in the early fully fruiting period, the quantity of the branches per 667 m^2 was 43 000, and the number of short branches was the largest, accounting for 82.0% of total number of branches, followed by long branches, middle branches and developmental branches.

Changes in Some Physiological Characteristics After Full Heading Stage in Flag Leaves of Super High-Yielding Inbred Rice

In a field experiment, rice cultivar Shanyou 63 was used as a check cultivar to investigate the changes in activity of peroxidase and contents of malondialdehyde and soluble protein after full heading stage in flag leaves of two super high-yielding inbred rice, including Shengtai 1 and Yuxiangyouzhan. The results showed that the peroxidase activities and soluble protein contents in the leaves of the three cultivars tended to increase gradually to peak values and thereafter descended during stage after full heading. Moreover, both the peroxidase activities and soluble protein contents of Shengtai 1 and Yuxiangyouzhan peaked at 8 days after full heading, which was compared with that of Shanyou 63 at 4 days later. Meanwhile, the malondialdehyde contents in the leaves of the three cultivars increased gradually after full heading stage. In addition, activities of peroxidase and contents of malondialdehyde and soluble protein in different cultivars were various at the same time. In general, for Shengtai 1 and Yuxiangyouzhan, the peroxidase activities and soluble protein contents were higher than those of Shanyou 63, whereas the malondialdehyde contents were lower compared with that of Shanyou 63. And these features could make the senescence of leaf become later and slower and photosynthetic product was more in Shengtai 1 and Yuxiangyouzhan than that in Shanyou 63.

Approach to the Ways for High-yielding Technique of Zhongzheyou No.8

[Objective] The paper was focused on the way how to increase the yield of hybrid rice Zhongzheyou No.8. [Method] The relationship among yield-related traits and their contribution to yield were investigated through correlation analysis, regression analysis and path analysis. [Result] The performance of ear, grain and weight in Zhongzheyou No.8 showed significant difference among yield levels. The enhancement of effective ears would restrain the number of total grains per ear. It was found that the direct contributions of main economic traits to yield were： number of fil ed grains per ear 〉 number of effective ears 〉1 000-grain weight 〉number of total grains per ear. [Conclusion] The promotion of high-yielding techniques was suggested as fol ows： on the basis of certain number of effective ears, number of fil ed grains per ear should be mainly focused with a consideration to grain weight.

Pectin methylesterase inhibitors GhPMEI53 and AtPMEI19 improve seed germination by modulating cell wall plasticity in cotton and Arabidopsis

The germination process of seeds is influenced by the interplay between two opposing factors,pectin methylesterase(PME)and pectin methylesterase inhibitor(PMEI),which collectively regulate patterns of pectin methylesterification.Despite the recognized importance of pectin methylesterification in seed germination,the specific mechanisms that govern this process remain unclear.In this study,we demonstrated that the overexpression of GhPMEI53is associated with a decrease in PME activity and an increase in pectin methylesterification.This leads to seed cell wall softening,which positively regulates cotton seed germination.AtPMEI19,the homologue in Arabidopsis thaliana,plays a similar role in seed germination to GhPMEI53,indicating a conserved function and mechanism of PMEI in seed germination regulation.Further studies revealed that GhPMEI53 and AtPMEI19 directly contribute to promoting radicle protrusion and seed germination by inducing cell wall softening and reducing mechanical strength.Additionally,the pathways of abscicic acid(ABA)and gibberellin(GA)in the transgenic materials showed significant changes,suggesting that GhPMEI53/AtPMEI19-mediated pectin methylesterification serves as a regulatory signal for the related phytohormones involved in seed germination.In summary,GhPMEI53 and its homologs alter the mechanical properties of cell walls,which influence the mechanical resistance of the endosperm or testa.Moreover,they impact cellular phytohormone pathways(e.g.,ABA and GA)to regulate seed germination.These findings enhance our understanding of pectin methylesterification in cellular morphological dynamics and signaling transduction,and contribute to a more comprehensive understanding of the PME/PMEI gene superfamily in plants.

The structure-directing role of heterologous seeds in the synthesis of zeolite

Zeolites have been widely used as catalysts,ion-exchangers,and adsorbents in chemical industries,detergent industry,steel industry,glass industry,ceramic industry,medical and healthfield,and environmentalfield,and recently applied in energy storage.Seed-assisted synthesis is a very effective approach in promoting the crystallization of zeolites.In some cases,the target zeolite cannot be formed in the absence of seed zeolite.In homologous seed-assisted synthesis,the structure of the seed zeolite is the same to that of the target zeolite,while the structure of the seed zeolite is different to that of the target zeolite in the heterologous seed-assisted synthesis.In this review,we briefly summarized the heterologous seed-assisted syntheses of zeolites and analyzed the structure-directing effect of heterologous seeds and surveyed the“common composite building units(CBUs)hypothesis”and the“common secondary building units(SBUs)hypothesis”.However,both hypotheses cannot explain all observations on the heterologous seed-assisted syntheses.Finally,we proposed that the formation of the target zeolite does need nuclei with the structure of target zeolite and the formation of the nuclei of the target zeolite can be promoted by either the undissolved seed crystals with the same CBUs or SBUs to the target zeolite or by the facilitated appropriate distribution of the specific building units due to the presence of the heterologous seed that does not have any common CBUs and SBUs with the target zeolite.