Responses of the Anthocyanin and Osmolyte Contents of the Capsicum annuum Cultivars Planted in Wenshan Prefecture of Yunnan Province to the Drought Stress Simulated by PEG-6000

[Objective] The aim of this study was to compare the drought resistance difference of the main Capsicum annuum cultivars planted in Wenshan Prefecture of Yunnan Province. [Method] The total anthocyanin, soluble sugar, soluble protein and free proline contents of the leaves of the five main C. annuum cultivars planted in Wenshan Prefecture, i.e., ZSZ75-1, ZSZ49-1-1, 12WS-18-1, 12ZH01 and ZS130, under the drought stress simulated by PEG-6000 were studied by using spectrophotometry, and the total osmoregulation abilities of the leaves were evaluated by using subordinate function. [Result] Under the drought stress simulated by PEG-6000, the total anthocyanin contents of the veins, mesophylls and whole leaves of the five cultivars were all as： ZSZ75-1〉ZSZ49-1-1〉12WS-18-1〉12ZH01〉ZS130, the soluble sugar contents as： 12ZH01 〉12WS-18-1 〉ZS130〉ZSZ49-1-1 〉ZSZ75-1, the soluble protein contents as： ZSZ75-1〉12ZH01〉ZSZ49-1-1〉12WS-18-1〉ZS130, and the free proline contents as： ZS130〉ZSZ75-1 〉12WS-18-1 〉ZSZ49-1-1 〉12ZH01. Furthermore, the differences among the total anthocyanin contents of the veins, mesophylls and whole leaves of the five cultivars all reached the extremely significant levels, whereas the differences among the contents of the soluble sugar, soluble protein and free proline did not reach the significant levels, the correlation degrees among the contents of the total anthocyanin, soluble sugar, soluble protein and free proline of different cultivars were also inconsistent, and the total osmoregulation abilities of the five cultivar leaves were as： ZSZ75-1 〉7SZ49-1-1 〉12WS-18-1 〉ZS130〉12ZH01. [Conclusion] The anthocyanin accumulation in the specific organs of the five C. annuum cultivars in Wenshan Prefecture is beneficial to the strengthening of the leaf osmoregulation abilities under drought stress, favoring the drought tolerance of the cultivars.

Genomic dissection of widely planted soybean cultivars leads to a new breeding strategy of crops in the post-genomic era

Soybeans specially the widely planted cultivars have been dramatically improved in agronomic performance and is well adapted to local planting environments after long-time domestication and breeding.Uncovering the unique genomic features of popular cultivars will help to understand how soybean genomes have been modified through breeding.We re-sequenced 134 soybean cultivars that were released and most widely planted over the last century in China.Phylogenetic analyses established that these cultivars comprise two geographically distinct sub-populations:Northeast China (NE) versus the HuangHuai-Hai River Valley and South China (HS).A total of 309 selective regions were identified as being impacted by geographical origins.The HS sub-population exhibited higher genetic diversity and linkage disequilibrium decayed more rapidly compared to the NE sub-population.To study the association between phenotypic differences and geographical origins,we recorded the vegetative period under different growing conditions for two years,and found that clustering based on the phenotypic data was closely correlated with cultivar geographical origin.By iteratively calculating accumulated genetic diversity,we established a platform panel of cultivars and have proposed a novel breeding strategy named "Potalaization"for selecting and utilizing the platform cultivars that represent the most genetically diversity and the highest available agronomic performance as the "plateau"for accumulating elite loci and traits,breeding novel widely adapted cultivars,and upgrading breeding technology.In addition to providing new genomic information for the soybean research community,the "Potalaization"strategy that we devised will also be practical for integrating the conventional and molecular breeding programs of crops in the post-genomic era.

Effect of Nutrient Management and Planting Geometry on Productivity of Hybrid Rice (<i>Oryza sativa</i>L.) Cultivars

Field experiments were conducted during the wet seasons of 2006 and 2007 at the Agricultural Experimental Farm of the Indian Statistical Institute, Giridih, a part of eastern plateau region of India. The study was designed to investigate the effect of planting geometry and nutrient management practices on productivity of two hybrid rice cultivars. Split-plot design with three replications was adopted to carry out the experiment by allocating combinations of treatments of planting geometry and rice cultivar in main-plots and nutrient management treatments in sub-plots. “CNRH-3” rice proved its efficiency in terms of grain yield that was also reflected in yield attributing characters such as number of productive tillers, number of grains per panicle, length of panicle, panicle weight, test weight and harvest index. Higher rice grain yield was registered when the cultivars grown in 20 cm × 20 cm planting geometry. Rice cultivars grown with the application of inorganic fertilizers alone produced maximum grain yield and also recorded higher values of ancillary characters. The maximum amount of N, P and K was taken up by the “CNRH-3” rice, whereas maximum residual soil fertility was recorded in “Pro Agro 6201” rice. Maximum N, P and K uptake values were recorded in 20 cm × 20 cm crop geometry and inorganic fertilizers treatment.

Effects of Planting Methods on Root Yield and Nutrient Removal of Five Cassava Cultivars Planted in Late Rainy Season in Northeastern Thailand

The objectives of this study were to evaluate growth, yield and nutrients removal of five cassava cultivars planted by different planting methods in late rainy season of northeastern Thailand. A split plot design was used in this study. The planting methods (vertical and horizontal) were assigned as main-plots. Cassava cultivars (Rayong-7, Rayong-11, Rayong-72, Huaybong-80 and E-dum) were assigned as sub-plots with four replications. Results showed that vertical planting gave significantly higher fresh storage root yield than those of horizontal planting, across five cassava cultivars. The cultivar Rayong-7 produced maximum fresh storage root yield across two planting methods, but not significantly different from Rayong 11, Huaybong 80 and Edum cultivars. Irrespective of nutrient removal, N, P and K removed ranges from 2.9 - 3.6, 0.8 - 1.3 and 5.3 - 7.9 kg per ton fresh root weight, respectively depending on cassava cultivar. The cultivar Rayong-7 removed the highest quantities of N, and the cultivar Rayong-11 removed maximum of P and K in the present study. Regardless of nutrient removal at different plant parts;N, P and K removed maximum quantities in leaf, stem and storage root, respectively. Planting method had no significant effect on N and P removal, but significant effect on K removal. The vertical planting removed K higher than those of horizontal planting.

Maximizing Land Use Efficiency by Intercropping Cowpea with Some Maize Cultivars under Different Maize Planting Geometries

Adjustment of planting geometry along with suitable maize cultivar can be a viable tool for maximizing land usage and net return. A two-year study was carried out at Serw Agricultural Experiments and Research Station, A.R.C., Domiate governorate, Egypt, during 2015 and 2016 seasons to evaluate intercropping cowpea with suitable maize cultivar and its planting geometry for maximizing land usage and net return. The treatments were the combinations between three maize cultivars (SC 30K08, TWC 310 and TWC 352) and three maize plant distributions (one plant/hill distanced at 25, 50 and 75 cm between hills, respectively). Ridge width with maize plant distribution formed maize planting geometry (25 cm × 140 cm, 50 cm × 140 cm and 75 cm × 140 cm). These treatments were compared in a split plot distribution in randomized complete block design with three replications. Maize cultivar SC 30K08 had the highest grain yield and its attributes compared with the other cultivars in both seasons. Also, maize planting geometry 25 cm × 140 cm resulted in the highest grain yield and its attributes compared with the other planting geometries in both seasons. Ear length, ear weight, 100-grain weight and grain yield/fad were affected significantly by maize cultivars × maize planting geometry. Intercropping cowpea with maize cultivar TWC 352 had the highest seed yield and its attributes compared with those intercropped with the other cultivars in both seasons. Also, maize planting geometry 75 cm × 140 cm resulted in the highest seed yield and its attributes through growing two cowpea rows between maize hills compared with the other maize planting geometries in both seasons. Number of pods/plant and seed yield/fad were affected significantly by maize cultivars × maize planting geometry. LER and LEC values of the intercrops were much greater than 1.00 and 0.25, respectively, for all the combinations indicating less land requirements of intercropping system than solid culture of both crops. Growing one row of maize cultivar TWC352 in both sides of bed 140 cm width with cowpea two rows in middle of the bed increased land productivity and net return compared with solid culture of maize.

Response of French Bean Cultivars to Plant Spacing Under Agroclimatic Condition of Baffa

This experiment was carried out at Mansehra during cropping season of 2013. There were three French bean cultivars and four different plant spacings. The experiment was laid out on a Randomized Complete Block Design （RCBD） with three replications. Different cultivars, plant spacings and their interactions significantly influenced all the parameters studied. Maximum days to flowering （59.33） and seed maturity （97.66） were recorded in cultivar Komal Green grown at 15 cm spacing, while, maximum 100-grain weight （42.20 g） was noted in cultivar Peshawar Local grown at 60 cm spacing. However, maximum fresh pod yield·plant^-1 （109.67 g）, number of seed·pod^-1 （7.99） and seed yield.hm2 （1 4373 kg） were recorded in cultivar Paulista grown at spacing of 45 cm. Whereas, maximum plant height （40.50 cm） was noticed in cultivar Paulista grown at 15 era plant spacing. While, the least number of days to flowering （50.33） and to seed maturity （85.66） were taken by cultivar Paulista grown at 60 cm plant spacing. Likewise, minimum seed yield （311.9 kg·hm^2） was recorded in plants of cultivar Komal Green spaced at 60 cm plant spacing. While, minimum fresh pod weight, plantI （67.00 g） and number of seed·pod^-1 （4.66） were attained in cultivar Peshawar Local grown at 15 cm plant spacing, whereas, minimum plant height （27.59 cm） and 100-grain weight （15.60 g） were recorded for cultivar Komal Green grown at 45 and 15 cm, respectively.

Stable Transformation of Three Cultivars of Kentucky Bluegrass (Poa pratensis L.) by Particle Bombardment of Mature Seed-Derived Highly Regenerative Callus

High embryogenic calli of three cutivars of Kentucky bluegrass, Md, Bd, and Gm, were induced from mature embryos, and were proliferated on medium K3 and K5. Embryogenic calli were transformed with plamids pDM803 and pBY520 by microprojectile bombardment. Fourty-two transgenic lines had been obtained. The highest efficiency of transformation reached to 3.7% for cv. Md, 2.8% for cv. Gm, and 5 % for cv. Bd. The micro nutriment of Cupric had significant effect on transformation. The embryogenic callus cultured in dim-light condition had higher transformation efficiency than the green callus cultured in light condition for one month before transformation. The selective regime and selective pressure on the putative transgenic plants were important for obtaining the desire number of transgenic plants. It also affected the copy number of integrated genes in the genomic DNA of transgenic plants.

Studies on Biomass Yield, Morphological Characteristics and Nutritive Quality of Napier Cultivars under Two Different Geo-Topographic Conditions of Bangladesh

The aim of the present study was to evaluate the performance of Napier cultivars in terms of forage yield, plant morphology and nutrient contents under two different agro-ecology and geo-topographic conditions. Three Napier cultivars being conserved by Bangladesh Livestock Research Institute (BLRI), namely-BLRI-Napier 1, (BN-1), BLRI-Napier 3 (BN-3) and Merkeron (BN-5) were selected to cultivate in severe drought prone areas (called Barind) and non-drought area at Savar (Modhupur terrace). Stem cuttings were planted in rows apart from 70 cm and 35cm spacing between plants. Data of 6 consecutive harvests from a period of approximately one year were collected and analyzed statistically by “R” software. The results showed that cultivar and location had a significant (P < 0.001) effect on biomass yield, plant height and leaf-stem ratio (LSR), while number of tillers were significantly varied with locations. BN-3 yielded the highest biomass (33.32 t/ha/harvest) at non-drought location (42.98 t/ha/harvest). The highest plant height was obtained in BN-1 (171.2 cm) at non-drought location (174.6 cm). Number of tillers per hill ranged from 25.4 to 26.3 among cultivars (P > 0.05) and the highest tillers were found at non-drought location (28.1 no). The best LSR was estimated from BN-5 (0.86) at drought location (0.95). The proximate analysis showed that CP, ADF and NDF in whole plant were varied significantly (P < 0.001), being the highest contents in BN-1 (10.69%, 46.20% and 54.58%, respectively). On the other hand, DM and ash contents did not differ significantly (P > 0.05) among cultivars which ranged from 15.80% to 17.13% and 13.10% to 14.58%, respectively. The highest CP content in whole plant was obtained at non-drought location (11.89%), while the lowest ash (10.57%) and NDF (52.71%) contents were obtained at the same location. The highest CP contents in leaf were found at non-drought (15.03%) and the lowest ash (9.86%) at the same location. The highest CP contents (5.90%) in stem were found at non-drought location, while the lowest ash (11.28%) and NDF (54.59%) contents were obtained at the same location. Finally, the experiment reveals the superiority in biomass yield and nutritional quality (in terms of CP content) with the ranking orders of BN-3 > BN-1 > BN-5 and BN-1 > BN-3 > BN-5. Therefore, it may be concluded that BN-1, BN-3, and BN-5 cultivars were well adapted in both drought and non-drought conditions, although performance showed better in later conditions. However, in terms of forage yield and overall nutrient composition, the performance of BN-3 was the best irrespective of locations.

Genetic characteristics of a wheat founder parent and a widely planted cultivar derived from the same cross

Founder parents have contributed significantly to the improvement of wheat breeding and production. In order to investigate the genetic characteristics of founder parents and widely planted cultivars, Mazhamai(M), Biyumai(B) and six sibling lines(BM1–6) derived from the cross M×B were phenotyped for eight yield-related traits over multiple years and locations and genotyped using the the wheat 90 K single nucleotide polymorphism(SNP) assay. BM4 has been used as a founder parent, and BM1 has been widely planted, whereas BM2, 3, 5, and 6 have not been used extensively for breeding or planting in China. Phenotypic comparisons revealed that BM4 and BM1 displayed a better overall performance than the other sibling lines. BM1 showed higher thousand-grain weight than BM4, whereas BM4 exhibited lower coefficient of variation for most of the yield-related traits across different years and locations, indicating that BM4 was widely adaptable and more stable in different environments. SNP analysis revealed that BM4 and BM1 inherited similar proportions of the M genome but are dissimilar to BM2, 3, 5, and 6. Both BM1 and BM4 have specific alleles that differ from the other BM lines, and most of these alleles are concentrated in specific chromosomal regions that are found to associate with favorable QTLs, these SNPs and their surrounding regions may carry the genetic determinants important for the superior performance of the two lines. But BM4 has more genetic diversity than BM1 with more specific alleles and pleiotropic regions, indicating that the genome of BM4 may be more complex than the other sibling lines and has more favorable gene resources. Our results provide valuable information that can be used to select elite parents for wheat and self-pollinating crop breeding.

A Standardized Method for Determining Tillering Capacity of Wheat Cultivars

Genotype and agronomic management greatly influence crop growth and grain yield in wheat (Triticum aestivum L.). To ensure sustainable production, seeding rate selection is important to maximize efficiency of every plant. Tillering can allow wheat plants to adjust growth relative to plant density and quality of growing conditions. This research sought to determine a method for assessing tillering of wheat cultivars and develop a standardized approach for characterizing cultivar tillering capacity. Nine cultivars with diverse genetic and phenotypic characteristics were seeded in 2017-2018 at Prosper, ND using various seeding techniques at differing plant spacing arrangements to evaluate tillering habit and spikes plant-1. Cultivars grown at population densities common in grower fields did not express full tillering potential. Spaced-plantings of cultivars promoted cultivar expression of tillering phenotype. The SOFATT (seed only a few, and then thin) method, where average spikes plant-1 was determined from multiple plants sampled from a cultivar grown at spaced-plantings (inter-row and intra-row spacing at 30 ± 12 cm), is recommended to properly assess tillering habits of wheat cultivars. Breeders and researchers can use results from SOFATT evaluations to determine tillering capacity rating for each cultivar based on raw or transformed z-score values for spikes plant-1.

Impact of Irrigation Water Salinity on Germination and Seedling Growth of Egyptian Barley Cultivars

The aim of this research was to assess the influence of saline irrigation water which prepared to obtain salt stress of 0.31,3.21,5.74,8.28 and 12.86 dS/m on seed germination,and early seedling growth of 10 cultivars(Giza 123,124,125,126,127,129,130,134,135 and 2000)of Egyptian barley grown in clay loam soil.Germination was tested in germination cups filled with clay loam soil moistened with different concentrations of saline water,in the growth chambers condition.Results indicated that,the highest values of germinated seeds were recorded mainly at fresh water(0.31 dS/m)at all germination periods.Also,the maximum values were recorded at investigated barley cultivars Giza 126,127 and 2000 for three studied periods(3,5 and 7 d),while Giza 129,130 and 135 got the same trend where the highest values for germinated seeds attained at the 5 d,7 d and at 3 d were 9.5 seeds,respectively.Barley cultivar Giza 126 had significantly higher root length(4.07 cm),shoot length(11.75 cm),root fresh weight(48.2 mg),shoot fresh weight(101.1 mg),root dry weight(7.1 mg),shoot dry weight(6.6 mg)and seedling vigor index(13.44).The 6 kDa protein bands had the same increasing after salt stress in cultivars Giza 123,127,129,134 and 135.Barley cultivars in clay soil can be classified into barley cultivars Giza 126,127 and 2000 as highly tolerance and barley cultivar Giza 129,123 and 127 as moderately tolerance and the rest is less.

Behavior of Watermelon Cultivars after Inoculation with Watermelon mosaic virus in Saudi Arabia

All seven watermelon cultivars that were screened for their reactions to a severe Saudi Arabian isolate of Watermelon mosaic virus(WMV-SA)that was found inducing a severe disease in watermelon in Riyadh region,were found to be susceptible and showed different virus-like symptoms upon mechanical inoculation.Sugar Baby,Crimson Sweet 1 and Crimson Sweet 2 cultivars showed milder symptoms and,therefore,got lower grand mean of weekly symptom ratings than Charleston Gray No.502,Jubilee,Black Diamond and Charleston Gray No.133 in both first and second experiments.Artificial inoculation with this isolate significantly reduced the plant height,fresh and dry weights of the tested cultivars.The reduction percentages in plant height of Sugar Baby and Crimson Sweet 2 were significantly lower than those of Crimson Sweet 1,Charleston Gray No.502 and Charleston Gray No.133 in both experiments.Also the reduction in percentages of fresh weights of Sugar Baby,Crimson Sweet 2 and Jubilee were significantly lower than reduction percentages of Crimson Sweet 1,Black Diamond and Charleston Gray No.133.The dry weight reduction percentages of Jubilee,Sugar Baby and Crimson Sweet 2 were lower than those of Charleston Gray No.502,Charleston Gray No.133,Black Diamond and Crimson Sweet 1 in both experiments.No correlation existed between the virus titer in the infected cultivars and their performances.In general,Sugar Baby and Crimson Sweet 2 performed better than the other cultivars as they had the lowest symptom severity ratings,the lowest percentages of plant height,fresh and dry weight reductions compared to the other tested cultivars.

Strong biosynthesis and weak catabolism of theanine in new shoots contribute to the high theanine accumulation in Albino/etiolated tea plant(Camellia sinensis)

Tea processed from albino/etiolated tea shoots is favored by consumers because of its high theanine accumulation.To explore why theanine accumulates highly in new shoots of albino/etiolated tea cultivars,we compared theanine content in shoots and roots of albino/etiolated and common green tea cultivars.Results suggested that high theanine accumulation in albino/etiolated tea shoots was likely not caused by higher theanine biosynthesis in roots.Further analyses suggested that CsAlaDC-catalyzed ethylamine biosynthesis and CsGOGAT1-catalyzed glutamate biosynthesis were more active,and CsGGT2-catalyzed theanine catabolism was weaker in new shoots of these albino/etiolated tea plant cultivars.Therefore,the high theanine accumulation in albino/etiolated shoots is probably contributed by the strong theanine biosynthesis and weak catabolism in new shoots.These findings provided more comprehensive insights into the high accumulation of theanine in new shoots of albino/etiolated tea cultivars,and the knowledge can be used in plant breeding for new cultivars with higher theanine accumulation.

2023年茶树遗传育种研究进展

文章总结概述了2023年度茶树遗传育种领域取得的主要进展,包括茶树育种基础理论的创新研究、茶树育种技术的创新探索、茶树新品种的授权与登记情况。2023年度,茶树的品质成分形成、生物及非生物胁迫响应、生长发育、叶色变异等分子调控机制,仍是育种基础理论研究的热点,获得的创新性成果为培育茶树新品种提供了明确的靶基因资源;茶树泛基因组图谱首次构建成功,进一步揭示了茶树基因组扩张的遗传基础;77个茶树品种授权获得植物新品种权,83个茶树品种通过非主要农作物品种登记,为茶产业稳健发展提供了强有力的支撑。

不同株型小花生品种氮素养分吸收利用特性

南方小花生植株高大的地方良种与矮化改良的品种并存。为探明其需氮规律,实现差异化施肥的高产管理,以湖南主栽的高秆地方良种安化小籽、矮秆现代品种湘黑小果为材料,设置4个基施复合肥用量0、450、600、750 kg/hm^(2),分别代表土壤背景(CK)、低肥(F30)、中肥(F40)、高肥(F50)水平,于4个生育时期测定并分析植株各器官氮含量、积累与分配状况。结果表明:氮含量以高秆品种果>叶>根>茎为序;矮秆品种则以叶>果>根>茎为序。叶、根氮含量表现为高秆<矮秆,而茎、果反之。增施肥料对氮含量的影响程度总体趋势为茎>叶>根>果,利于营养器官的氮素同化吸收。氮积累量两品种各器官以叶>果>茎>根为序。除苗期外,其余时期的全株、叶、茎氮积累量表现为高秆>矮秆;根在苗期、结荚期为高秆<矮秆,其余时期相反;果则为高秆<矮秆。施肥利于营养器官前期的氮素积累。氮素分配率两品种均以叶最高,荚果和茎其次,根最少。地上部为高秆>矮秆,而地下部反之,说明矮秆植株吸收的氮素更利于转运到荚果。氮素利用效率均为矮秆>高秆,氮素生产效率、氮肥偏生产力两品种均以F40、F30最高,过度施肥降低氮素利用效率。综上,矮秆品种氮素积累量对增肥的响应度较低,总积累量虽然较少而在荚果中分配较多,并具有更高的氮素利用效率;品种株型特点应作为南方典型贫瘠酸性红壤区小籽花生生产上确定施肥量的主要依据。

种植密度与施氮量互作对不同玉米品种产量和水分利用效率的影响

【目的】合理增密配合适量施氮是玉米丰产增效的重要技术途径,研究氮密互作对玉米生长、生育期内耗水量及水分利用率的影响,可为玉米增密控氮条件下水资源的高效利用提供技术依据。【方法】分别于2022和2023年在吉林省设置田间试验,采用良玉99和德美亚3两个玉米品种,设置5、7、9万株/hm^(2)3个种植密度和0、100、200、300 kg N·hm-24个施氮水平,研究种植密度和施氮量对不同品种玉米各生育时期植株干重、土壤含水量、耗水量、水分利用效率和籽粒产量及水分生产力的影响。【结果】种植密度显著影响玉米植株干重和籽粒产量,但品种间响应趋势不同。良玉99在种植7万株/hm^(2)的产量较5、9万株/hm^(2)两年平均分别显著提高11.1%和18.3%,德美亚3种植7、9万株/hm^(2)较5万株/hm^(2)两年平均分别显著提高10.5%和9.3%。施氮显著提高玉米植株干重和产量,且与品种、密度存在显著交互作用。与N0相比,良玉99施氮增产38.0%—60.7%,德美亚3增产24.4%—38.2%,良玉99施氮产量增幅更高。随种植密度的提高,2个品种在低施氮量与高施氮量下产量差距均呈逐渐增大趋势,且良玉的表现更为明显。种植密度和施氮量也显著影响玉米对水分的消耗和利用,且密度与品种间存在交互作用。德美亚3的生育期总耗水量随密度的增加呈持续上升趋势,而良玉99以种植7万株/hm^(2)显著高于其他密度。不同密度条件下,2个品种的耗水量均随施氮量的增加而持续上升。受年际降雨量及分布的影响,玉米不同生育时期的水分利用效率对种植密度和施氮表现出复杂的响应趋势。良玉99在种植5、7万株/hm^(2)的水分生产力较9万株/hm^(2)两年平均增幅为8.6%和10.4%;德美亚3则在种植7万株/hm^(2)的水分生产力最高,较5、9万株/hm^(2)增加5.8%和5.3%。施氮对玉米水分生产力的影响在不同密度下存在差异,总体上低密度下施氮处理间差异较小,而中、高密度下显著增大。相比德美亚3,良玉99的水分生产力在中、高密度施氮后的增幅更高。相关分析表明,氮密互作通过影响玉米植株各生育阶段对水分的利用而显著影响产量和水分生产力。【结论】氮密互作显著影响东北雨养区玉米产量与水分利用,良玉99和德美亚3在适度增密至7万株/hm^(2)配合200 kg N·hm-2施氮量条件下可获得较高产量和水分生产力。

紫花苜蓿微型蔬菜栽培基质及品种筛选研究

以紫花苜蓿品种‘WL525HQ’为试材,采用单因素完全随机设计,设定6种不同栽培基质配比及2种不同种植方式,通过测定其发芽率、地上地下生物量和根系形态,筛选适宜紫花苜蓿微型蔬菜栽培的基质及种植方式;以28个紫花苜蓿品种为试材,采用单因素完全随机设计,通过测定皂苷含量、刀豆氨酸含量,筛选出作为微型蔬菜生产的最佳紫花苜蓿品种;通过灰色关联度分析刀豆氨酸含量与公司、产地和秋眠级的关联度,以期为筛选紫花苜蓿微型蔬菜生产的基质、种植方式和品种提供参考依据。结果表明:紫花苜蓿微型蔬菜在草炭∶蛭石=1∶1(S1处理)的混合基质栽培下,地上、地下部生物量最高;相较于催芽移栽,直接播种的紫花苜蓿长势更好;28个紫花苜蓿品种中,‘WL363HQ’的刀豆氨酸含量最低,可作为紫花苜蓿微型蔬菜生产的最佳品种。紫花苜蓿品种产地、秋眠级与刀豆氨酸含量关联度较大,可为紫花苜蓿微型蔬菜品种筛选提供参考依据。

增密种植条件下基于主动冠层传感器GreenSeeker的春玉米氮营养无损诊断研究

针对当前东北地区玉米种植密度偏低、氮肥管理粗放及应用传统氮肥诊断方法存在的限制与不足等问题,以协同玉米增产与氮肥高效为目标,在黑龙江省哈尔滨市开展田间试验,设置2个种植密度、2个玉米品种和6个氮水平小区试验,应用新式主动冠层传感器GreenSeeker,于玉米V5~V10期动态取样监测,建立回归模型,分析增密种植条件下不同玉米品种氮营养诊断指标变化,探究种植密度与品种对主动冠层传感器实时氮营养指标估测模型的影响。结果表明,适量施氮有利于改善植株氮营养状况、促进玉米增产;氮、密互作共同影响籽粒产量,种植密度由D6增至D8,籽粒产量与施氮量线性平台拐点由196.0、200.4 kg N·hm^(-2)分别增加至208.8、209.4 kg N·hm^(-2);氮浓度稀释曲线Y=34.0X-0.37在黑龙江地区适用,氮营养指数(Nitrogen nutrition index,NNI)诊断阈值主要受种植密度影响;GreenSeeker植被指数(Normalized difference vegetation index,NDVI)与地上部生物量、植株吸氮量、叶面积指数相关性较好,决定系数达0.75~0.89;NNI与NDVI相关模型决定系数较低,仅为0.49~0.58;NDVI对植株氮浓度诊断结果不佳。NDVI可用来准确诊断玉米氮营养状况,但需综合考虑氮肥用量、密度与品种耐密性对诊断模型准确性的影响。研究将GreenSeeker传感器最新诊断技术引入玉米增密群体氮营养诊断,评估氮浓度稀释曲线适用性,相关结果可为玉米增密群体的氮精准管理提供理论依据,未来具备区域大面积应用潜力。

安徽省林木植物新品种保护现状及对策

植物新品种权是我国知识产权的重要组成部分,我国从法律层面保护植物新品种权人的权益,鼓励育种者在新品种培育、推广上的投入和研发。本文介绍了近年来安徽省林木植物新品种的授权情况和保护现状,分析了新品种保护中存在的品种权保护水平偏低、保护执法力量不足、成果转化效率不高等问题,并从加强培训宣传、加强行政保护、加强科研攻关和推广示范等方面提出新品种保护对策。

Influence of plastic film mulching and planting density on yield,leaf anatomy,and root characteristics of maize on the Loess Plateau

In rainfed areas of northwestern China,maize production is constrained mainly by low temperature during early growth and water limitation during the entire growth period.Plastic film mulching is commonly used to increase maize yield in this area,because it increases topsoil temperature and moisture content as well as water use efficiency.However,the physiological and anatomical bases of maize yield improvement with plastic film mulching are not well understood.The effects of plastic film mulching and planting density on maize yield,photosynthetic characteristics,respiration,leaf anatomy,and root growth were studied in a two-year field experiment conducted on the Loess Plateau of China in 2017 and 2018.The experiment used a split-split plot design with two mulching treatments(plastic film mulching and no mulching),two planting densities(7.5×104 and10.5×104 plants ha-1),and two maize cultivars,Zhengdan 958 and Xianyu 335.Compared with no mulching,plastic film mulching increased maize yields by 31.1%–46.4%in 2017 and3.6%–34.7%in 2018.Compared with low planting density,high planting density significantly increased and slightly reduced yields of both cultivars in the dry year 2017 and the rainy year 2018,respectively.Plastic film mulching increased photosynthesis and respiration as well as leaf stomatal density and aperture.Photosynthetic rate,dark respiration,and stomatal conductance and aperture were lower at high planting than at low planting density.Maize yield was positively correlated with photosynthesis,dark respiration,and stomatal aperture.Mulching increased root dry weight and length in the 0–20 cm soil layer and root activity at maturity.Overall,the changes in root growth and leaf anatomy resulted in increased photosynthesis and dark respiration,and the increased photosynthesis contributed to the increase in grain yield and biomass production under plastic film mulching conditions.Our results increase understanding of the physiological mechanisms by which plastic film mulching increases maize yield in water-and temperature-limited areas.