Chinese Cultivars Research Articles

Profiling and associations of seed nutritional characteristics in Chinese and USA soybean cultivars

Soybean is an important oilseed crop both in China and the USA owing to its nutritional and functional characteristics. The formation of nutritional components in soybean is influenced by the genetic background of cultivar as well as environmental factors. Here, we profiled protein, oil, fatty acids, soluble sugars and isoflavone in 218 Chinese and 115 USA soybean cultivars which were grown across three locations for two years in China. Significant differences (p < 0.05) were observed among the cultivars, countries of origin and maturity groups for all the nutritional characteristics measured. Higher levels of oil (20.5%), linoleic acid (56.4%), sucrose (58.6 mg g−1), total soluble sugars (109 mg g−1) and total isoflavone (3,161.8 μg g−1) were observed in USA cultivars, while higher levels of protein (42.4%) and oleic acid (23.2%) were observed in Chinese cultivars. From the principal component analysis, protein, oil, oleic acid, linoleic acid and isoflavone were identified as the major discriminative characteristics in the soybean cultivars. Furthermore, correlation analysis presented various beneficial associations among the different nutritional traits. The nutritional characteristics varied in their associations with the geographical factors (latitude, longitude and altitude), indicating that the origin of the cultivars has a pronounced effect on the nutritional characteristics. This study reveals the profiles of nutritional characteristics of Chinese and USA soybean cultivars and also identified unique cultivars that can be utilized for various industrial uses and breeding programs aimed at improving soybean nutritional characteristics.

Identification and analysis of a differentially expressed wheat RING-type E3 ligase in spike primordia development during post-vernalization.

We identified a RING-type E3 ligase (TaBAH1) protein in winter wheat that targets TaSAHH1 for degradation and might be involved in primordia development by regulating targeted protein degradation. Grain yield per spike in wheat (Triticum aestivum), is mainly determined prior to flowering during mature primordia development; however, the genes involved in primordia development have yet to be characterized. In this study, we demonstrated that, after vernalization for 50days at 4°C, there was a rapid acceleration in primordia development to the mature stages in the winter wheat cultivars Keumgang and Yeongkwang compared with the Chinese Spring cultivar. Although Yeongkwang flowers later than Keumgang under normal condition, it has the same heading time and reaches the WS9 stage of floral development after vernalization for 50days. Using RNA sequencing, we identified candidate genes associated with primordia development in cvs. Keumgang and Yeongkwang, that are differentially expressed during wheat reproductive stages. Among these, the RING-type E3 ligase TaBAH1 (TraesCS5B01G373000) was transcriptionally upregulated between the double-ridge (WS2.5) stage and later stages of floret primordia development (WS10) after vernalization. Transient expression analysis indicated that TaBAH1 was localized to the plasma membrane and nucleus and was characterized by self-ubiquitination activity. Furthermore, we found that TaBAH1 interacts with TaSAHH1 to mediate its polyubiquitination and degradation through a 26S proteasomal pathway. Collectively, the findings of this study indicate that TaBAH1 might play a prominent role in post-vernalization floret primordia development.

Development of novel clubroot resistant rapeseed lines (Brassica napus L.) effective against Japanese field isolates by marker assisted selection.

Clubroot is an important disease infectible to cruciferous plants and a major threat to rapeseed production in Japan. However, no clubroot resistant rapeseed cultivars have been released. We surveyed pathotype variation of six isolates collected from rapeseed fields and found they were classified as pathotype groups 2 and 4 using Japanese F1 Chinese cabbage cultivars. We produced the resynthesized clubroot resistant Brassica napus harboring two resistant loci, Crr1 and Crr2, by interspecific crossing and developed resistant rapeseed lines for southern and northern regions by marker-assisted selection and backcrossing. We improved the DNA marker for erucic acid content to remove linkage drag between Crr1 and high erucic acid content and successfully selected lines with clubroot resistance and zero erucic acid for northern regions. A novel line, ‘Tohoku No. 106’, suitable for southern regions showed stable resistance against all six isolates and high performance in infested fields. We conclude that Crr1 and Crr2 are important genes for CR rapeseed breeding and marker-assisted selection is effective in improving clubroot resistance.

Exogenous metabolites spray, which identified from metabolomics analysis and transcriptomic analysis, can improve salt tolerance of Chinese cabbages (Brassica rapa L.ssp pekinensis)*

ABSTRACT Soil salinization is one of the causes of the decline of the available cultivated land. By improving the salt tolerance of vegetables, the abandoned salinized land can be effectively utilized, saving the arable land for major crops. We investigated the salt tolerance of hundreds of Chinese cabbage cultivars, by which the two most tolerant and sensitive cultivars were selected and studied by metabolome and transcriptome analyses. The results showed that, under salt stress, metabolites’ response was not closely correlated with gene expressions in the tested Chinese cabbages. However, some KEGG pathways were significantly regulated at both metabolic and transcriptional levels. Furthermore, we identified several critical metabolites in the co-regulated pathways, including acetyl-CoA, pyruvic acid, ATP, nicotinic acid and Coenzyme Q10, which could alleviate the salt stress level in the tested Chinese cabbage. Thus, our findings provide candidate agents which can be used to improve salt tolerance in Chinese cabbage.

EVALUATION OF SALINITY STRESS EFFECTS ON CHANGES IN PHOTOSYNTHETIC PIGMENTS, HYDROGEN PEROXIDE AND OSMOLYTES IN SENSITIVE AND TOLERANT CULTIVARS OF WHEAT CROP

Investigation of wheat response to salinity stress can help to better understand the effective defense mechanisms of salinity stress tolerance. For this purpose, biochemical and physiological traits related to salinity tolerance in wheat cultivars were evaluated at Gorgan University of Agricultural Sciences and Natural Resources in 2019. Experimental factors, included two wheat crop cultivars (Sarc and Chinese spring as tolerant and susceptible wheat cultivars, respectively) and sampling time series (zero or control, 24, 48, 72, and 96 h) were examined in a factorial experiment based on a completely randomized design with three replications. Salinity stress was applied with sodium chloride at a concentration of 250 mM to uniform 10-day-old seedlings at the two-leaf stage, followed by sampling of shoot tissue. The studied traits were hydrogen peroxide (H2O2 ), chlorophyll a, chlorophyll b, total chlorophyll, chlorophyllase, carotenoids, proline, and total carbohydrates. Results of analysis of variance (ANOVA) indicated significant effects of genotype, time, and interaction of genotype × time (except H2O2 and total carbohydrates) on all the studied traits. Results of interaction of genotype × time showed although the trend of changes in the studied traits, depending on the type of cultivar and the sampling time were different, but generally, the susceptible Chinese spring cultivar contained higher levels of chlorophyllase and carotenoids than the control time at the end of sampling time and also higher H2O2 levels than the Sarc tolerant cultivar, while the Sarc tolerant cultivar, on the other hand, contained higher levels of chlorophyll a, chlorophyll b, total chlorophyll, and proline than the control time at the end of sampling time and also greater total carbohydrates than the susceptible Chinese spring cultivar. The results confirm the higher capacity of the antioxidant defense system of Sarc tolerant cultivar than the susceptible Chinese spring cultivar. Therefore

CHARACTERIZATION OF PUTATIVE HEAT SHOCK TRANSCRIPTION FACTOR (Hsf2) GENE INVOLVED IN REGULATING THE EXPRESSION OF HSP90 IN WHEAT UNDER TERMINAL HEAT STRESS

Wheat, being staple food grain crop, is highly sensitive to heat stress. The effect is more evident under present threat of global climate change. Very limited information about heat-responsive transcription factor is known in wheat. A putative Heat Shock Factor (HSF) was cloned from wheat under HS. The gene was titled as Hsf2 (acc No. KP063542). The nucleotide sequence was found to be 1551 bp long with open reading frame (ORF) of 1125 bp (5’UTR of 213bp and 3’UTR of 213bp). The amino acid sequence showed the presence of HSF_ DNA binding domain having high degree of similarity (homology) with other HSF coding gene of related species (Aegilops tauschii with 95% homology and 100% homology with Chinese spring cultivar of Triticum aestivum). The protein was observed to be localized in the nucleus. Phosphorylation study showed the presence of phosphorylated threonine at seventeen sites in amino acid sequence. Expression analysis of Hsf2 showed maximum relative fold expression (2.04fold) in the leaves of HD2967 under HS, as compared to control. The transcript abundance was observed maximum in thermotolerant cv., as compared to thermo susceptible. Current study established positive correlation between the expression of Hsf2 and HSP90 under HS. Hsf2, being regulator of HSPs can be used as potential molecular marker for screening wheat germplasm for thermo tolerance. It will pave the way for the development of ‘climate-smart’ wheat crop.

Assessing Volatiles in Three Chinese Dwarf Cherry Cultivars during Veraison and Maturation Using Headspace-Solid Phase Microextraction with Gas Chromatography-Mass Spectrometry.

Chinese dwarf cherry is a native shrub in northwest China with a rich and unique fruit aroma. This study aims to determine the changes in volatile profiles during the maturation period, which provides a theoretical basis for the optimal harvest times and the breeding of aroma-rich varieties. The variation in the production of 164 volatile compounds from three Chinese dwarf cherry cultivars, namely, “Jing’ou 1”, “Jing’ou 2”, and “Jing’ou 3”, were investigated by headspace-solid phase microextraction (HS-SPME)-GC–MS. These volatiles mainly constituted alcohols, carbonyls, esters, terpenoids, and hydrocarbons. Their maturation process could be divided into three stages, namely prophase, metaphase, and anaphase. Prophase contained an abundance of hydrocarbons and carbonyls, primarily benzaldehyde being dominant among all volatiles. During metaphase, volatiles remained at a low level of abundance and diversity. Anaphase coincided with full maturation and was associated with esters and terpenoids; in particular, “Jing’ou 3” presented more compound diversity and a high level of acetate esters. The periods including the week prior to veraison and the week during maturation were particularly critical in volatile formation in Chinese dwarf cherries. This study reveals that the low level or lack of hexanal might be one of the distinctive characteristics separating Chinese dwarf cherries from other Cerasus or Rosaceae fruits.

Comparative proteomics of three Chinese potato cultivars to improve understanding of potato molecular response to late blight disease

BackgroundLate blight disease (LBD) caused by the pathogen Phytophthora infestans (PI), is the most devastating disease limiting potato (Solanum tuberosum) production globally. Currently, this disease pathogen is re-emerging and appearing in new areas at a very high intensity. A better understanding of the natural defense mechanisms against PI in different potato cultivars especially at the protein level is still lacking. Therefore, to elucidate potato proteome response to PI, we investigated changes in the proteome and leaf morphology of three potato cultivars, namely; Favorita (FA), Mira (MA), and E-malingshu N0.14 (E14) infected with PI by using the iTRAQ-based quantitative proteomics analysis.ResultsA total of 3306 proteins were found in the three potato genotypes, and 2044 proteins were quantified. Cluster analysis revealed MA and E14 clustered together separately from FA. The protein profile and related functions revealed that the cultivars shared a typical hypersensitive response to PI, including induction of elicitors, oxidative burst, and suppression of photosynthesis in the potato leaves. Meanwhile, MA and E14 deployed additional specific response mechanism different from FA, involving high induction of protease inhibitors, serine/threonine kinases, terpenoid, hormone signaling, and transport, which contributed to MA tolerance of LBD. Furthermore, inductions of pathogenesis-related proteins, LRR receptor-like kinases, mitogen-activated protein kinase, WRKY transcription factors, jasmonic acid, and phenolic compounds mediate E14 resistance against LBD. These proteins were confirmed at the transcription level by a quantitative polymerase chain reaction and at the translation level by western-blot.ConclusionsWe found several proteins that were differentially abundant among the cultivars, that includes common and cultivar specific proteins which highlighted similarities and significant differences between FA, MA, and E14 in terms of their defense response to PI. Here the specific accumulation of mitogen-activated protein kinase, Serine/threonine kinases, WRKY transcription played a positive role in E14 immunity against PI. The candidate proteins identified reported in this study will form the basis of future studies and may improve our understanding of the molecular mechanisms of late blight disease resistance in potato.

Dynamics of Race Structures of Pyricularia oryzae Populations Across 18 Seasons in Guangdong Province, China.

Rice blast, caused by Pyricularia oryzae, is one of the most damaging fungal diseases affecting rice. Understanding how the pathogen's race structure varies over time supports the efforts of rice breeders to develop improved cultivars. Here, the race structure of P. oryzae in Guangdong province, China, where rice is cropped twice per year, was assessed over 18 seasons from 1999 through 2008. The analysis was based on the reactions of a panel of seven differential Chinese cultivars to inoculation with a set of 1,248 isolates of P. oryzae in the province. The "total race frequency" parameter ranged from 14.7 to 39.7%, and the "race diversity index" ranged from 0.63 to 0.93. Twelve (ZA63, ZA31, ZA29, ZA21, ZA13, ZA9, ZB30, ZB17, ZB8, ZB2, ZC14, and ZC8) and two (ZD8 and ZD3) races were recognized as specific to indica and japonica rice types, respectively. Of the 59 distinct races identified, only two indica type races (ZC13 and ZC15) were identified as population-common, and nine indica type races (ZB1, ZB5, ZB6, ZB7, ZB13, ZB15, ZC5, ZC13, and ZC15) and one japonica type race (ZG1) were deemed to be population-dominant; the "total top two race isolate frequency" parameter ranged from 29.8 to 74.5%. On the host side, dynamics of resistance structures of the differential set were divided into three patterns: Both Tetep and Kanto 51 expressed the highest and most stable resistance, both Sifeng 43 and Lijiangxintuanheigu conveyed much lower and unstable resistance, and Zhenlong 13, Dongnong 363, and Heijiang 18 performed intermediate and seasonally dynamic resistance. Three interesting points distinguishing race structures of P. oryzae populations in southern and northeastern China were also discussed.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

A comparative study on nutritive peculiarities of 24 Chinese cowpea cultivars

The nutritive peculiarities and original distribution of 24 Chinese cowpeas cultivars, achieved from Jiangxi, Jilin, Shanxi and Shaanxi provinces in China, were evaluated. Their nutritional components were determined and nutrient characteristics were discussed. Principal component analysis (PCA) was applied to classify the cowpea samples based on their nutrient composition. The results discovered that the proximate composition varied among 24 cowpeas in protein (17.30–27.23%), fat (1.87–3.14%), high level of dietary fiber (29.49–38.54%) and resistant starch (3.18–31.33%). The total tocopherol varied from 74.20 to 187.07 μg/g. PCA results presented that the 24 cowpeas cultivars were automatically grouped with provinces of origin, indicating a relationship between nutrient composition and cultivating religion for cowpeas. The results of this study provide us the information on the nutrients characteristic of current cowpeas in China, and give a guideline on cowpea cultivating optimization and processing.

Genome-wide association analysis of stripe rust resistance in modern Chinese wheat

BackgroundStripe rust (yellow rust) is a significant disease for bread wheat (Triticum aestivum L.) worldwide. A genome-wide association study was conducted on 240 Chinese wheat cultivars and elite lines genotyped with the wheat 90 K single nucleotide polymorphism (SNP) arrays to decipher the genetic architecture of stripe rust resistance in Chinese germplasm.ResultsStripe rust resistance was evaluated at the adult plant stage in Pixian and Xindu in Sichuan province in the 2015–2016 cropping season, and in Wuhan in Hubei province in the 2013–2014, 2016–2017 and 2018–2019 cropping seasons. Twelve stable loci for stripe rust resistance were identified by GWAS using TASSEL and GAPIT software. These loci were distributed on chromosomes 1B, 1D, 2A, 2B, 3A, 3B, 4B (3), 4D, 6D, and 7B and explained 3.6 to 10.3% of the phenotypic variation. Six of the loci corresponded with previously reported genes/QTLs, including Sr2/Yr30/Lr27, while the other six (QYr.hbaas-1BS, QYr.hbaas-2BL, QYr.hbaas-3AL, QYr.hbaas-4BL.3, QYr.hbaas-4DL, and QYr.hbaas-6DS) are probably novel. The results suggest high genetic diversity for stripe rust resistance in this population. The resistance alleles of QYr.hbaas-2AS, QYr.hbaas-3BS, QYr.hbaas-4DL, and QYr.hbaas-7BL were rare in the present panel, indicating their potential use in breeding for stripe rust resistance in China. Eleven penta-primer amplification refractory mutation system (PARMS) markers were developed from SNPs significantly associated with seven mapped QTLs. Twenty-seven genes were predicted for mapped QTLs. Six of them were considered as candidates for their high relative expression levels post-inoculation.ConclusionThe resistant germplasm, mapped QTLs, and PARMS markers developed in this study are resources for enhancing stripe rust resistance in wheat breeding.

Ecological genomics of Chinese wheat improvement: implications in breeding for adaptation

BackgroundChina has diverse wheat varieties that adapt to very different environments divided into ten agro-ecological zones. A better understanding of genomic differences and patterns of selection among agro-ecological zones could provide useful information in selection of specific adaptive traits in breeding.ResultsWe genotyped 438 wheat accessions from ten zones with kompetitive allele specific PCR (KASP) markers specific to 47 cloned genes for grain yield, quality, adaptation and stress resistance. Phylogenetic trees and principle component analysis revealed clear differences in winter and spring growth habits. Nucleotide diversity (π) and π ratio (πCL/πMCC) suggested that genetic diversity had increased during breeding, and that Chinese landraces (CL) from Zones I-V contributed little to modern Chinese cultivars (MCC). π ratio and Fst identified 24 KASP markers with 53 strong selection signals specific to Zones I (9 signals), II (12), III (5), IV (5), V (6), and VI (6). Genes with clear genetic differentiation and strong response to selection in at least three zones were leaf rust resistance gene Lr34 (I, II, III and IV), photoperiod sensitivity gene Ppd-D1 (I, II, III, IV and V), vernalization gene Vrn-B1 (V, VII, VIII and X), quality-related gene Glu-B1 (I, II and III) and yield-related genes Sus1-7B (I, II, III, IV and IX), Sus2-2A (I, II, III., IV and VI) and GW2-6B (II, V and VI).ConclusionsThis study examined selection of multiple genes in each zone, traced the distribution of important genetic variations and provided useful information for ecological genomics and enlightening future breeding goals for different agro-ecological zones.

Transcriptome and metabolome analyses reveal the regulation of peel coloration in green, red Chinese prickly ash (Zanthoxylum L.)

Peel colour is an important external economic characteristic of Chinese prickly ash cultivars (Zanthoxylum bungeanum Maxim.). To gain insight into their coloration mechanisms, we performed an integrated analysis of green and red peels using combined metabolomic and transcriptomic analyses. Pelargonin-O-hexoside-O-rhamnoside-O-hexoside, pelargonidin 3,5-diglucoside, peonidin O-hexoside, cyanidin O-syringic acid and peonidin 3-O-glucoside were found to be the key anthocyanins. Transcriptome data indicated that the anthocyanidin synthase genes and UDP-glucose flavonoid 3-O-glucosytransferase genes were significantly increased to promote the redness of the peels. In addition, we discussed the role of R2R3-MYB transcription factors in coloration, of which the c80935 and c226097 genes may be the key regulatory factors for anthocyanin biosynthesis. Generally, this is the first study to identify and reveal the main anthocyanins in Chinese prickly ash peels during different developmental periods. The results of this research lay the foundation for understanding the regulation of coloration in Chinese prickly ash peels.

Genomic atlases of introgression and differentiation reveal breeding footprints in Chinese cultivated rice

The long history of cultivation and breeding has left a variety of footprints in the genomes of Asian cultivated rice (Oryza sativa L.). In this study, we focus on two types of genomic footprints, introgression and differentiation, in a population of more than 1200 Chinese rice accessions. We found that a Xian/indica and a temperate Geng/japonica accession respectively contained an average of 19.3-Mb and 6.8-Mb alien introgressed chromosomal segments, of which many contained functional sequence variants, quantitative trait loci, or genes controlling flowering, grain, and resistance traits. Notably, we found most introgressions, including the known heterotic loci Hd3a and TAC1, were distributed differentially between the female and male parents of three-line indica hybrid rice, indicating their potential contribution to heterosis. We also found many differentiated regions between subgroups within a subpopulation contained agronomically important loci, such as DTH7, Hd1 for heading date, and qCT7 for cold tolerance, providing new candidates for studying local adaptation or heterosis. Tracing these footprints allows us to better understand the genetic exchange or differentiation underlying agronomic traits in modern Chinese rice cultivars. These findings also provide potential targets for rice genetic research and breeding.

Development of an Efficient Bioassay Method for Testing Resistance to Bacterial Soft Rot of Chinese Cabbage

Pectobacterium carotovorum subsp. carotovorum (Pcc) causes bacterial soft rot on a wide range of crops worldwide, especially in countries with warm and humid climates. This study was conducted to establish an efficient screening method for resistant cultivars of Chinese cabbage to bacterial soft rot. Resistance degrees of 65 commercial Chinese cabbage cultivars to the Pcc KACC 10225 isolate were investigated. For further study, three Chinse cabbage cultivars (Taebong, Hadaejangkun, CR Alchan) showing different level of resistance to the bacterium were selected. The development of bacterial soft rot on the cultivars was tested according to several conditions such as growth stage of Chinse cabbage seedling, inoculum concentration, and incubation temperature after inoculation. On the basis of the results, we suggest that an efficient screening method for resistant Chinses cabbage to Pcc is to inoculate twenty one-day-old seedlings with a bacterial suspension of Pcc at a concentration of 1×107 cfu/ml, and to incubate the plants in a dew chamber at 25° for 24 hr and then to cultivate in a growth room at 25° and 80% relative humidity with 12-hr light per day.

Essential oil from the rhizomes of the Saudi and Chinese Zingiber officinale cultivars: Comparison of chemical composition, antibacterial and molecular docking studies

BackgroundEssential oils have been known to possess useful biological activities and are widely used in aromatherapy owing to their peculiar aroma. The present study compared the essential oil composition isolated from the Chinese and Saudi ginger cultivars and determined their antimicrobial activity. MethodsThe volatile compounds were extracted by a hydrodistillation method and the composition was analysed by gas chromatography coupled with mass spectrometry (GC–MS). The antibacterial activity of oils was tested against the pathogenic Gram positive and Gram negative bacterial strains. Potential bioactivities were predicted with the help of Prediction of activity spectra for substances (PASS) software and the molecular docking studies on the mycobacterial protein were carried out using Pyrex with Vina wizard tool. ResultsA total of 43 and 30 volatile components were identified in the Chinese and Saudi varieties respectively. α–zingiberene in the Chinese and ar-curcumene in Saudi ginger oil were found to be the major volatile constituents. Ginger oil showed better antibacterial activity against Gram positive than Gram negative bacteria. Molecular docking studies showed ar-curcumene to have high binding affinity for the inhibition of bacterial protein. ConclusionThe presence of the biological active compounds such as α–zingiberene, ar-curcumene and β-sesquiphellandrene makes ginger essential oil a potential source of antimicrobialagents and as an additive/preservative in the food industry.

Genetic and epigenetic variations in barley (Hordeum vulgare L.) using SSR and MSAP approaches

Barley (Hordeum vulgare L.) is the fourth largest cereal crop in the world with extensive adaptability in diverse environments. There is increasing evidence that epigenetics contributes to plant evolution and adaptation. However, epigenetic variation in barley and their correlations with genetic variation remains largely unknown. In this study, we investigated epigenetic and genetic diversity in 48 Tibetan wild distribution (TWD) barley accessions, 24 Chinese cultivars (CC), and 24 foreign cultivars (FC) using DNA methylation-sensitive amplified polymorphism and simple sequence repeats. We found a relatively high level of epigenetic (I = 0.639 and h = 0.450) and genetic (I = 0.637 and h = 0.446) diversity in barley, and a significant correlation between epigenetic and genetic variation in barley (R2 = 0.160, P < 0.001). No differences in genetic variation were observed among TWD, CC and FC populations. However, the TWD population had significantly higher epigenetic diversity (I = 0.607 and h = 0.424, P < 0.001) than both cultivated populations (FC: I = 0.584 and h = 0.402; CC: I = 0.544 and h = 0.372). Also, the TWD population had significantly higher average hemi-methylation (20.35%) and full-methylation (25.37%) levels than both cultivated populations (FC: 16.13% and 20.98%, respectively; CC: 15.98% and 18.95%, respectively). This study has provided valuable information on DNA methylation variation across diverse barley accessions and indicated that epigenetic variations might be another factor contributing to barley diversity.

Control of Panama disease of banana by intercropping with Chinese chive (Allium tuberosum Rottler): cultivar differences

Panama disease (Fusarium wilt disease) caused by Fusarium oxysporum f. sp. cubense race 4 (FOC) severely threatens banana (Musa spp.) production worldwide. Intercropping of banana with Allium plants has shown a potential to reduce Panama disease. In this study, six cultivars of Chinese chive (Allium tuberosum Rottler) were selected to compare their differences in antifungal activity and active compounds. Three cultivars Duokang Fujiu 11, Fujiuhuang 2, and Duokang Sijiqing with higher levels of antifungal compounds were further used for intercropping with banana in the pots and field to compare their effects on growth and disease incidence of banana.The six cultivars showed significant differences in antifungal activity against FOC mycelia growth in both leaf volatiles and aqueous leachates. The aqueous leachates displayed stronger antifungal activity than the volatiles. FJH cultivar showed the best inhibitory effect among all six cultivars. Contents of three main antifungal compounds dipropyl trisulfide (DPT), dimethyl trisulfide (DMT), and 2-methyl-2-pentenal (MP) in volatiles and aqueous leachates varied considerably among cultivars. Pot and field experiments showed that intercropping with three selected Chinese chive cultivars significantly improved banana vegetative growth, increased photosynthetic characteristics and yield but decreased disease incidence of Panama disease.Our results indicate that intercropping with Chinese chive shows potential to reduce banana Panama disease and selection of appropriate cultivars is vital for effective disease control.

In vitro efficiency of embryo rescue of intra- and interspecific hybrid crosses of sweet cherry and Chinese cherry cultivars

Hybrid cherry seedlings are very hard to obtain as the embryos easily abort during development and loose germination ability, especially some interspecific hybrids. An in vitro technique of embryo rescue has been developed for intra- and interspecific hybrids with the embryos by crossing 4 sweet cherry genotypes as maternal, and these have been planted in South China where the climate is not ideal for planting sweet cherry due to its hot and humid climate in summer and warm climate in winter. The success of embryo rescue approach is affected by several factors, in which the genotypes are one of the main factors for embryo germination and significant differences were found with the same genotypes that were used differently either as maternal or paternal in cross breeding. ‘Chaoyang-1’ (‘CY-1’) as mother performed the best, and ‘Zijing’ (‘ZJ-1’) and ‘CY-1’ were the best parents as fathers in cross breeding. The embryo development stage, breaking dormancy method and in vitro culture condition significantly affected the efficiency of seedlings production. When the development of their embryos reached to 0.5 to 0.7, then the young fruit was harvested and stored at 4 °C for 35 days were found to be the best initiating materials for culturing, and the embryo germination rates after removal of the embryo coat reached up to 69.84 ± 2.75 %, and their shoots were robustly and fastly grown. The medium when combined with different concentrations of plant growth regulators (PGRs) were tested, the optimal medium for immature embryo culturing was found to be 1/2 MS supplemented with 2 mg L−1 BA and 1.8 mg L−1 IAA, the multiplication of shoots culture media was MS +0.3 mg L−1 BA +0.4 mg L−1 IAA or MS +0.7 mg L−1 BA +0.1 mg L−1 IAA, the 1/2 MS medium supplemented with 0.3 mg L−1 IBA and 1.1 mg L−1 IAA showed the best for the rooting of shoots. Taken together, this system by integrating the genotypes, embryo development and in vitro culture condition with pre-treatments together significantly improved the rates of production of hybrid cherry seedlings. This is the first study to systematically explore all these factors on cherry embryo rescue in order to produce hybrid seedlings to breed new cultivars for the subtropical monsoon climatic areas like South China and provide new insights to keep the micropropagation of hybrid shoots with different PGRs.

Impact of Cultivar, Harvest Date and Threshing Parameter Settings on Floret and Carthamidin Yield of Safflower

The industrial need for safflower (Carthamus tinctorius L.) increased over the last decade due to its potential use as food colorant. Safflower is mainly cultivated in Asia for its use as floret. In Germany, an economically attractive cultivation for floret use would require a mechanization of harvest. In order to develop a mechanical harvesting system, field experiments were conducted at the experimental station Ihinger Hof of the University Hohenheim in 2017 and 2018. Safflower was harvested with a combine harvester to obtain the florets. Two safflower (i) cultivars were harvested with (ii) three threshing parameter settings on (iii) five harvest dates to evaluate threshed floret yield, dry matter and carthamidin content, and carthamidin yield. Results showed that the maximum threshed floret yield was achieved at the latest harvest date (784.78–1141.76 kg ha−1), while the highest carthamidin contents were observed depending on cultivar on the first two harvest dates (0.53–3.14%). The decisive and resulting amount of carthamidin yield reached its maximum with the Chinese cultivar and the threshing parameter setting P3 between the fourth and fifth harvest date in 2018 (19.05–19.36 kg ha−1). Highest dry matter contents were achieved at the last harvest date (62.67–77.77%). Individual capitula weight and carthamidin content decreased with later harvest dates. Further investigations should clarify whether the individual capitula weight and carthamidin content correlate with each other or are independent of the date of harvest. This could be a decisive criterion for the selection of cultivars for harvesting florets with a combine harvester. Reduced costs of machine harvesting compared to hand harvesting will make the cultivation of safflower for the food coloring industry in Germany more attractive in the future.