Breeding against mycorrhizal symbiosis:Modern cotton (Gossypium hirsutum L.) varieties perform more poorly than older varieties except at very high phosphorus supply levels

Cotton (Gossypium hirsutum L.) is an importantfiber cash crop,but its root traits related to phosphorus (P) acquisition,including mycorrhizal root traits,are poorly understood.Eight cotton varieties bred in northwestern China that were released between 1950 and 2013 were grown in pots with or without one arbuscular mycorrhizal fungal (AMF) species(Funneliformis mosseae) at three P supply levels (0,50 and 300 mg P as KH_(2)PO_(4)kg^(-1)).Eleven root traits were measured and calculated after 7 wk of growth.The more recent accessions had smaller root diameters,acquired less P and produced less biomass,indicating an (inadvertent) varietal selection for thinner roots that provided less cortical space for AMF,which then increased the need for a high P fertilizer level.At the two lower P levels,the mycorrhizal plants acquired more P and produced more biomass than non-mycorrhizal plants (3.2 vs.0.9 mg P per plant;1.8 vs.0.9 g biomass per plant at P_(0);14.5 vs.1.7 mg P per plant;and 4.7 vs.1.6 g biomass per plant at P_(50)).At the highest P level,the mycorrhizal plants acquired more P than non-mycorrhizal plants (18.8 vs.13.4 mg per P plant),but there was no difference in biomass (6.2 vs.6.3 g per plant).At the intermediate P level,root diameter was significantly positively correlated with shoot biomass,P concentration and the P content of mycorrhizal plants.The results of our study support the importance of the outsourcing model of P acquisition in the root economics space framework.Inadvertent varietal selection in the last decades,resulting in thinner roots and a lower benefit from AMF,has led to a lower productivity of cotton varieties at moderate P supply (i.e.,when mycorrhizal,the average biomass of older varieties 5.0 g per plant vs.biomass of newer varieties 4.4 g per plant),indicating the need to rethink cotton breeding efforts in order to achieve high yields without very high P input.One feasible way to solve the problem of inadvertent varietal selection for cotton is to be aware of the trade-offs between the root do-it-yourself strategy and the outsourcing towards AMF strategy,and to consider both morphological and mycorrhizal root traits when breeding cotton varieties.

Distribution and Selective Effects of Vrn-A1,Vrn-B1,and Vrn-D1 Genes in Derivative Varieties from Four Cornerstone Breeding Parents of Wheat in China

Vernalization, the process of a long exposure to low temperature to induce flowering in plants, is essential for plants to adapt to cold winters. The presence of vernalization genes Vrn-A1, -B1, and -D1 in four cornerstone breeding parents of wheat in China （Funo, Mentana, Yanda 1817, and Bima 4） and 322 derivative varieties （mostly winter wheat） from these parents were determined using PCR based molecular method. The frequencies of the VRN-1 genes in these derivative varieties were in order of Vrn-Dl（67.1%）〉 Vrn-Bl（19.6%）〉 Vrn-Al（5.3%）, which are similar as the former conclusion that Vrn-D1 is associated with the latest heading time, Vrn-A1 the earliest, and Vrn-B1 intermediate values. The frequencies of Vrn-Al and Vrn-B1 loci in the derivative varieties from winter wheat zones were higher than that from spring winter zones. Based on the wheat breeding history in China and the fact of non-random distribution of Vrn-A1 and Vrn-B1 in the derivative varieties from the four parents, there could be a strong selective effect on VRN-1 genes in different regions where the derivative varieties were cultivated.

Breeding of New Large Cocoon and Hypersilkgeneous Tussah Varieties with Eurytopicity

The new tussah varieties have been bred by selecting large, high quality and midterm based on the indexes of high cocoon shell rate and high stress re- sistance. In the meantime, whole cocoon weight, hatchabillty and other economic parameters were considered in new variety breeding. Through 14 generations of hybrid breeding for over 7 years, two new tussah varieties had been successfully obtained. The breeding results of DW were as follows ： the 1 000-cocoon weight was 11.57 kg; the whole cocoon weight was 12.06 g; the cocoon shell rate was 12.22% ; and the larval-pupal integrated survival rate was 95.87%. The breeding re- sults of GH were as follows： the 1 000-cocoon weight was 11.52 kg; the whole cocoon weight was 11.95 g; the cocoon shell rate was 12.66% ; and the larval-pupal integrated survival rate was 90.37%.

American glabrous rice utilized in breeding of super-high-yielding and good-quality varieties

The yield potential of current rice varieties has reached a high plateau and fluc-tuated within a narrow range. Based on the theory and practice of rice breedingfor super-high-yield, we put forward a concept of " Two high and one early",which means high biomass and high efficiency of light energy conversion, as wellas fast growing in the early growth stage. The agronomic characters of 15 U. S

New Varieties of Populus tomentosa Carr. and Breeding Techniques

The main morphological characteristics, producing area and growth characteristics of sixteen new varieties of Chinese white poplar （Populus tomentosa Carr. ） are reported, aiming at providing reference for breeding and extension of new varieties.

Participatory Breeding on Arabica Coffee to Obtain Superior Local Varieties to Support Origin Specialty Coffee Product Development in Indonesia

A participatory breeding on Arabica coffee involving farmers and plant breeders to select superior local varieties has been conducted at Lintong highland （North Sumatra）, Gayo highland （Central Aceh, Northern Sumatra） and Kendenan Plateau （Enrekang, South Sulawesi）. The aim of using this method was to find out superior varieties of Arabica coffee having appropriate specific traits and adaptable to such locations and accelerating the process of variety adoption by local farmers. Selection process was initiated by the farmer（s） based on high yielding performance by using their native experiences. The next step was conducted by plant breeder in collaboration with coffee farmers and other relevant scientists to evaluate more detail of cup quality, resistance to leaf rust and/or parasitic nematode as well as yielding potential and agronomic traits at different farmer＇s sites for several years observations. Research finding showed that three selected varieties namely Sigarar Utang, Gayo 1 and Gayo 2 had already been released by Minister of Agriculture for commercial planting at North Sumatera and Gayo highland. They performed excellent cup profile with high yielding ability （more than 1 t/ha） and tolerant to leaf rust disease. Therefore, it could support origin specialty coffee product at Gayo and Lintong highlands. However, observation over of selected local variety at Kendenan Plateau namely Salongge variety performed lower yielding ability （below 1 t/ha） and less stable yield over years as well as more heterogenous population in their offsprings than that of existing released varieties planted at the same location. Therefore, it could not be released as local varieties which adapted to specific location.

Participatory Plant Breeding and Selection Impact on Adoption of Improved Sweetpotato Varieties in Uganda

This study analyzed the impact of participatory plant breeding （PPB） and participatory variety selection （PVS） on the adoption of improved sweetpotato varieties （ISPV） in central Uganda. The study quantitatively assessed how the two approaches influence farmers＇ uptake of the improved sweetpotato varieties and also determined other factors influencing this adoption. This was done by estimating a robust standard errors logit model. Both PPB and PVS positively and significantly influenced the likelihood of adoption of improved sweetpotato varieties at 5% and 10% levels, respectively. Other variables that positively influenced the adoption are extension services, training in sweetpotato production, farming experience, and off-farm income of the household. Farmers who participated in the plant breeding and variety selection processes were 37 and 6.7 times more likely to adopt the improved sweetpotato varieties than those who had not, respectively. Farmers who were trained specifically in sweetpotato production were 8.8 times more likely to adopt the improved varieties than those who had not received this type of training.

Breeding for multiresistant rice varieties

From 1977 to 1987, new rice varieties Xiangkang 32xuan 5, Xiangzaoxian 3 and HA79317—4 were bred. They had resistance to bacterial blight (BB), rice blast (BL), brown planthopper(BPH), whitebacked planthopper (WBPH), with high-yielding and good rice quality.

Breeding and Characterization of Yunchachunhao, a New Tea Variety with Full Aroma and High Quality

[Objective] The aim of this study was to select a tea variety with full aro- ma and high quality. [Method] The quality of Yunchachunhao was identified using Yunkang 10 and Fudingdabaicha as the controls in variety comparison test, using Yunkang 10 and Dangdidayezhong as the controls in reginal test. [Result] In variety comparison test, the yield of Yunchachunhao was 39.3% more than that of Yunkang 10, and 29.6% more than that of Fudingdabaicha. In reginal test, the yield of Yun- chachunhao was 2.5% （Baoshan） and 10.2% （Lancang） more than that of Yunkang 10. The roast-dried green tea of Yunchachunhao was characterized by flowery fla- vor, good taste and bright green infused leaves. It got the total scores of 91.13 in quality identification, which was higher than that of Fudingdabaicha （90.75） and Yunkang 10 （88.85）. The steam fixed green tea of Yunchachunhao contained 28.0% polyphenols and 2.7% amino acids; and the ratio of polyphenols to amino acids was 10.4, lower than that of Fudingdabaicha （10.6） and Yunkang 10 （17.3）. Yun- chachunhao had better resistance to drought and blister blight than Yunkang 10. [Conclusion] The survival rates of cuttings and transplanted seedlings of Yun- chachunhao are higher than that of control varieties, suggesting it has better adapt- ability and can be promoted in the large-leaf tea planting area of Yunnan Province.

Breeding of High-yield and High-quality Hybrid Maize Nuoda 1 with Multiple Resistances

Nuoda 1 is a high-yield and high-quality hybrid maize variety with multiple resistances, which is bred by Shandong Academy of Agricultural Sciences. Its female parent is Lx6958 and male parent is H318. In 2013, Nuoda 1 was approved by the Crop Variety Approval Committee of Shandong Province. In the regional trial of maize variety in Shandong Province from 2010 to 2011, the average yield within two years was 8 862.0 kg/hm^2, which enhanced by 4.0% compared with the control Zhengdan 958. In 2012, average yield of production test was 10 119.0 kg/hm^2, which enhanced by 4.4%. Nuoda 1 was introduced in the research from the aspects of characteristics, breeding foundation and breeding process.

Breeding of New Winter Wheat Variety Nongda No.399

The winter wheat variety Nongda No. 399 was developed by Agriculture and Biotechnology College of China Agricultural University and Hebei Jincheng Seed Corporation Ltd. with the characteristics of high yield, high-resistance and wide adaptation. The variety is suitable for direct seeding in the winter wheat planting area of the central and southern Hebei Province.

Analysis of the Nationally Registered Rice Varieties in the Last Decade

The nationally registered rice varieties during 2006-2015 were analyzed and there were 49.4 varieties on average annually registered in the last decade. In terms of the structure of varieties, there was a decreasing trend for the proportion of three-line hybrid rice varieties but a rapid increase for that of two-line hybrid rice varieties. The percentage of rice varieties developed by scientific research institu- tions was decreasing but that developed by seed companies kept a rapid increase, indicating the commercial breeding conducted by seed companies has become a principal model in rice breeding. With regard to grain quality of varieties, the con- ventional rice varieties showed an increasing trend while the hybrid rice varieties had a decreasing trend in the proportion of high quality varieties, indicating hybrid rice needs improving more in grain quality in breeding programs.

Breeding of a New Peanut Variety Shanghua No.6 with High Shelling Percentage and Big Fruit

Shanghua No.6, a new peanut variety with high shelling percentage and bigfruit, was bred through sexual hybridization（female parent Pukehua No.2 × male parent Yuanza 9102） by Shangqiu Academy of Agriculture and Forestry Sciences. In the big peanut regional tests in north China in 2011-2012, Shanghua No.6 had the average yield of pod and seed respectively of 4 695.30 kg/hm^2 and 3 514.73 kg/hm^2;in the production test in 2013, its average yield of pod and seed were 4 531.0 5kg/hm^2 and 3 312.15 kg/hm^2. Its crude fat content was 50.46-53.46%, oleic acid content was 50.9-51.7%, and oil oleic acid/linoleic acid value was 1.69-1.76. The variety was high-resistant to brown spot and focal spot, susceptible to black spot,resistant to net blotch and stem rot. Its 100-pod weight was 256.2 g, 100-seed weight 111.2 g, and shelling percentage was 74.75%. The variety was certificated by National Crop Variety Approval Committee in 2014（identification number：2014010）, which was suitable for planting in Shandong, Henan, Hebei, Liaoning,Beijing, north of Huaihe River in Jiangsu and Anhui provinces.

Breeding of New Maize Variety ‘Wan-de No.1' with High Quality, High Yield and Multi-resistance

Considering the ecological environment of Sichuan area, an experiment was conducted to breed new maize varieties with high yield, high quality, multi re- sistance and wide adaptability. According to the principle of gene recombination, the authors combined the local tropical germplasm with PB germplasm, which was rich in disease-resistant, lodging-resistant and drought-tolerant genes, and the integration was used as the innovative strategy for breeding. Inbred-line ＇LSC 107＇ was suc- cessfully bred and the new maize hybrid ＇Wande No.l＇ was bred by crossing ＇LSC 107＇ with ＇Yi 99-19＇. The results showed that the maize hybrid had good performance, including high yield, good stability, high quality, excellent disease re- sistance and lodging resistance, and wide adaptation. So it was adaptable for plant- ing in plain and hilly areas of Sichuan Province. With hybrid recombination between local tropical germplasm and PB inbred lines, the inbred-line had high general com- bining ability and strong adaptability, and the hybrid had high yield, high quality and wide adaptability, and had broad prospects of popularization and application.

An Innovative Project of Wheat Breeding

The objectives of wheat breeding in Sichuan and Chongqing were incon- sistent with the requirements of wheat production in 1980s. The new direction, to breed new wheat variety with high and stable yield, good quality, resistance to dis- eases, tolerance to spike sprouting, large head, white and big grain and outstanding commercial property, was put out in this article based on the development of wheat production, market economy and the needs of people. Depending on the selection and breeding work of Mianyang Institute of Agricultural Sciences for more than 20 years, new wheat varieties Mianyang 25, Mianyang 26, Mianyang 27, Mianyang 28, Mianyang 31, Xikemai 1 and Xikemai 6 were developed successively, which made a great contribution to the wheat breeding wheat breeding and production in SJchuan and even in China and the national food security.

Review and Prospects on Rice Breeding and Extension in China

A large number of new varieties, especially hybrid rice, have been developed and released in China since 1998. The yield potential and grain quality of hybrid rice have also been improved significantly both for three-line and two-line hybrid rice including indica and japonica types as well. The trends on extension of rice varieties in China since 1986 has been marked by the increasing number of new varieties, decreasing annual planting area per variety, decreasing number of varieties with a large-scale extension area, while both the renewal rate and the proportion of core varieties with cross-provincial extension have remained unchanged. This current major problems and future goals of rice breeding and extension in China were also discussed.

Tracing founder haplotypes of Japanese apple varieties: application in genomic prediction and genome-wide association study

Haplotypes provide useful information for genomics-based approaches,genomic prediction,and genome-wide association study.As a small number of superior founders have contributed largely to the breeding history of fruit trees,the information of founder haplotypes may be relevant for performing the genomics-based approaches in these plants.In this study,we proposed a method to estimate 14 haplotypes from 7 founders and automatically trace the haplotypes forward to apple parental(185 varieties)and breeding(659 F 1 individuals from 16 full-sib families)populations based on 11,786 single-nucleotide polymorphisms,by combining multiple algorithms.Overall,92%of the single-nucleotide polymorphisms information in the parental and breeding populations was characterized by the 14 founder haplotypes.The use of founder haplotype information improved the accuracy of genomic prediction in 7 traits and the resolution of genome-wide association study in 13 out of 27 fruit quality traits analyzed in this study.We also visualized the significant propagation of the founder haplotype with the largest genetic effect in genome-wide association study over the pedigree tree of the parental population.These results suggest that the information of founder haplotypes can be useful for not only genetic improvement of fruit quality traits in apples but also for understanding the selection history of founder haplotypes in the breeding program of Japanese apple varieties.

Breeding and Application Prospects of a New Quinoa Variety Longli 1

Longli 1 （ Chenopod/um qu/noa Willd） was the first new quinoa variety in China, which was bred by Pasture and Green Agriculture Institute of Gansu Academy of Agricultural Sciences through the methods of line breeding, cultivation and domestication. In muhipeint regional test, the average yield of Longli 1 was 2 100. （30 kg/hm2, which was increased by 9.6% compared to Jingle qulnoa. Langli 1 was a mid-late mature quinoa variety. The plant was brcom-shape, with the plant height of 181.2 - 223.6 cm, the growth period of 128 - 140 d, and the branch number of 23 - 27. The seeds were round pill shaped, with 1 000-grain weight of 2.40 -3.46 g. The contents of crude protein, fat, proline and total phosphorus in seeds were 171.5 -187.8, 56.5 -59.3, 5.5 -6.9 and 4.5 -6.8 g/kg, re- spectively. I_ongli 1 presented resistance against downy mildew and leaf spot, with strong disease-resistant ability. In multipeint regional test and production test, Longli 1 displayed lodging resistance with strong regeneration ability. It also presented resistance to cold, drought, saline and alkaline, and barren, with wide adaptability. Longh 1 was suitable for planting in mountains, plain field and irrigation area with frost-free period greater than 120 d, rainfall more than 250 mm, and altitude 1 500 -3 000 m. The application prospects of quinoa were also put forward in the paper.

Breeding of a New High-yield, High-oil and Web Blotch-resistant Big Peanut Variety Shanghua 511

Shanghua 511 is a high-yield, high-oil and web blotch-resistant big peanut variety bred by the Shangqiu Academy of Agriculture and Forestry Sciences through sexual hybridization （Yuhua 18♀×Shangyan 9658♂）. In the wheat-peanut interplanting regional experiment conducted in Henan Province during 2012-2013, the average pod and seed yield of Shanghua 511 were 5906.19 and 4149.3 kg/hm2, respectively. In the wheat-peanut interplanting production experiment conducted in Henan Province in 2013, the average pod and seed yield of Shanghua 511 were 6036.45 and 4309.50 kg/hm2, respectively. In the kernels of Shanghua 511, the contents of crude fat, oleic acid and linoleic acid were 56.62%, 44.9% and 33.4% respectively, and the oleic/linoleic acid ratio was 1.34. This variety had high resistance to web blotch and medium resistance to leaf spot, viral diseases, root rot and collar rot. The 100-pod weight, 100-kernel weight, shelling percentage and growth period of Shanghua 511 were 270.6, 110.9 g, 70.6% and 120 d, respectively. Shanghua 511 passed the approval of Henan Provincial Crop Variety Approval Committee in August, 2015, and is suitable for spring sowing and wheat interplanting in the surrounding area of Henan Province and the area to the north of Huaihe River.

Breeding and Application of Guidan 903,a New High-yield and Good-quality Maize Variety

To meet the demand of maize production in Guangxi and even the southwest region of China and realize the upgrading and undating of maize varieties which will continuously improve the yield and quality of maize,a new big-ear maize variety Guidan 903 with high yield,stable yield and good quality was established by the Maize Research Institute of Guangxi Academy of Agricultural Sciences with two self-selected inbred line GRL17349 and GRL21191 as female and male parents seperately.The average yield of this variety were 7429.5 and 7000.5 kg/hm^(2)in Guangxi Maize Regional Trial and Production Test respectively,which increased by 6.3%and 5.6%than the control(Guidan162).It was approved by Guangxi Zhuang Autonomous Region Crop Variety Certification Committee in June 2020(Approval No.Gui sheng yu 2020083).Determined by the Cereal Quality Supervision and Testing Center of Ministry of Agriculture and Rural Affairs(Bejjing),the grain bulk density,ratio of crude protein,crude fat,crude starch and lysine of Guidan 903 were 782 g/L,9.41%,6.19%,71.45%,0.35%respectively.This variety has the characterisics of strong resistance to collapse and disease,good quality,high and stable yield and wide adaptability.Furthermore,its seed yield is high with easy production technology and low cost.