Genetic diversity and inferred ancestry of Asian lotus(Nelumbo nucifera) germplasms in Thailand and Vietnam

Tropical lotus(Nelumbo) is an important and unique ecological type of lotus germplasm.Understanding the genetic relationship and diversity of the tropical lotus is necessary for its sustainable conservation and utilization.Using 42 EST-SSR(expressed sequence tag-simple sequence repeats) and 30 SRAP(sequence-related amplified polymorphism) markers,we assessed the genetic diversity and inferred the ancestry of representative tropical lotus from Thailand and Vietnam.In total,164 and 41 polymorphic bands were detected in 69 accessions by 36 EST-SSR and seven SRAP makers,respectively.Higher genetic diversity was revealed in Thai lotus than in Vietnamese lotus.A Neighbor-Joining tree of five main clusters was constructed using combined EST-SSR and SRAP markers.Cluster Ⅰ included 17 accessions of Thai lotus;cluster Ⅱ contained three Thai accessions and 11 accessions from southern Vietnam;and cluster Ⅲ was constituted by 13 accessions of seed lotus.Consistent with the results from the NeighborJoining tree,the genetic structure analysis showed that the genetic background of most Thai and Vietnamese lotus was pure,as artificial breeding has been rare in both countries.Furthermore,these analyses indicate that Thai and Vietnamese lotus germplasms belong to two different gene pools or populations.Most lotus accessions are genetically related to geographical distribution patterns in Thailand or Vietnam.Our findings showed that the origin or genetic relationships of some unidentified lotus sources can be evaluated by comparing morphological characteristics and the data of molecular markers.In addition,these findings provide reliable information for the targeted conservation of tropical lotus and parent selection in breeding novel cultivars of lotus.

Introgression the Salinity Tolerance QTLs <i>Saltol</i>into AS996, the Elite Rice Variety of Vietnam

This study focus on developing new salinity tolerance and high yielding rice lines, using markers assisted backrossing (MABC). Total of 500 SSR markers on 12 rice chromosomes were screened for parental polymorphic markers. Of which, 52 primers in the Saltol region were checked with the two parents varieties to identify polymorphic primers for screening the Saltol region of the breeding populations. For each backcross generation of ASS996/FL478, approx. 500 plants were screened with 63 polymorphic markers distributed on 12 chromosomes. The two BC1F1 plants P284 and P307 which had the highest recipient alleles up to 89.06% and 86.36%, were chosen for the next backcrossing. Three BC2F1 plants with the recipient alleles up to 94.03% and 93.18% were used to develop BC3F1 generation. The best BC3F1 plant was P284-112-209 with all the recipient alleles and Saltol region. The four plants P307-305-21, P284-112-195, P284-112-198, P284-112-213 were the second ranking with only one loci heterozygous (applied 63 markers covered on 12 chromosomes). These five plants were chosen as the breeding lines for result of Saltol-AS996 introgression. The breeding line BC4F1 having 100% genetic background of donor variety is ready for develop new salinity tolerant variety ASS996-Saltol to cope with climate change.

Isolation and Selection of Beneficial Microorganism Used for Peanut Growing in Sandy Soil of Binhdinh Province, Vietnam

With the aim to apply the beneficial microorganisms to peanut （groundnut （Arachis hypogaea）） growing in sandy soil of Binhdinh province in Vietnam, the paper was conducted to study the isolation, selection of N-fixing, phosphate, potassium solubilizing and slime producing microorganism from sandy soil and peanut root samples, and evaluate the capability of selected isolates to adapt to the sandy soil condition. The isolation and selection of beneficial microbes were based on the biological activity of isolates, which was determined by acetylene reduction assay and nodulation on the peanut for Rhizobium spp., by testing the capability to solubilize Ca3（PO4）2 or fenspat in the growth medium for phosphate, potassium solubilizing microbes, and by measurement of the viscosity of Hansen medium for slime producing microorganism. All isolates were evaluated for the effectiveness on the nutrition uptake and growth of peanut by carrying out at the greenhouse and field experiments. To evaluate the adaptation of selected isolates to the sandy soil condition, the experiments were carried out in the laboratory to determine the microbial density in suitable medium, containing different NaCI concentrations or with different pH or at different temperatures. The results showed that rhizobial strain RA18 had an N-fixing activity value of 3,458 ＋ 10.95 nmol C2H2/plant and can supply 30% of N required for peanut. The bacterial strain P 1107 is able to solubilize phosphate and can increase phosphorus uptake by 30% in peanut. Further, inoculation of peanut with the bacterial strain S3.1 can save 30% required mineral potassium, and the Lipomyces strain PT5.1 can produce the slime, which can provide the sandy soil to keep moisture for 15 d longer than the control without the inoculation. All selected isolates are able to grow at temperatures from 20 ℃ to 35 ℃, pH from 4.5 to 6.0 and the salinity of 0.2%o-0.6%o NaCI, and can well adapt to the sandy soil conditions.

Molecular cloning, characterization, and antioxidant function of catalase in Lymantria dispar asiatic (Lepidoptera: Lymantriidae) under avermectin stress

The critical antioxidant catalase(CAT)breaks down hydrogen peroxide induced by environmental stresses.Here we cloned full length catalase cDNA from Lymantria dispar asiatic(LdCAT).Bioinformatic analyses showed that open reading frames of LdCAT contains 1524 bp,encoding 507 amino acids with molecular weight of 126.99 kDa,theoretical pI of 5.00,aliphatic index of 29.92,grand average of hydropathicity of 0.764,and instability index(II)of 46.56.Protein BLAST and multiple sequence alignment indicated that LdCAT had high identity with CAT from other insects,especially lepidopterans.In a phylogenetic analysis,LdCAT was most similar to CAT from Spodoptera litura and S.exigua.Quantitative realtime polymerase chain reaction showed that LdCAT transcripts in all instar larvae and the five tissues tested,verifying the ubiquity of LdCAT in L.disapr.Moreover,LdCAT of third instar larvae was significantly upregulated after they fed on avermectin at sublethal and LC10 doses.The highest relative transcript levels were found 2 h after an avermectin spray at LC90,and in the cuticula,rather than heads,fat bodies,malpighian tubes,and midguts after a spray avermectin at a sublethal concentration.The expression level of LdCAT under pesticide stresses here suggested that CAT is an important antioxidant enzyme of L.disapr defensing against pesticide stress and may be a good target for controlling this pest.

Enhancing soil water holding capacity and provision of a potassium source via optimization of the pyrolysis of bamboo biochar

Rapid expansion of cultivated bamboo negatively impacts on biodiversity and soil microbial community.As such,it is important to properly manage and use bamboo to prevent and control such issues.This study focuses on optimizing pyrolysis conditions to produce bamboo biochar for agricultural soil amendment,particularly soil potassium(K)and water holding capacity.Bamboo chips were pyrolyzed under nitrogen gas at 400,600,and 800℃ for 1 and 2 h of retention.A total of six biochar products were created:400-1(i.e.,400℃ in 1 h),400-2,600-1,600-2,800-1,and 800-2.The 600℃ bamboo biochar products were observed to have the greatest potential in increasing soil K and water holding capacity.The 600-1 product had the highest potassium content(4.87%),with a water holding capacity of 3.73 g g^(−1),while the 600-2 product had the second-highest potassium content(4.13%)and the highest water holding capacity(4.21 g g^(−1))and cation exchange capacity.The K release in 600℃ products was larger and slower than that of the 400℃ and 800℃ products,respectively.The results also indicated that the physicochemical characteristics of bamboo biochar,such as yield,pH,surface area,water holding capacity,and K content,were significantly impacted by temperature,retention time,or a combination of these parameters.The outcomes from this study are a valuable reference for bamboo biochar production targeting agricultural soil amendment,particularly when it is directed at increasing soil K and water holding capacity.

Correction to:Enhancing soil water holding capacity and provision of a potassium source via optimization of the pyrolysis of bamboo biochar

The article“Enhancing soil water holding capacity and provision of a potassium source via optimization of the pyrolysis of bamboo biochar”,written by Tran Thi Thu Hien,Toshiki Tsubota,Tomoyuki Taniguchi and Yoshi-yuki Shinogi was originally published electronically on the publisher’s internet portal on 20th of October 2020 without open access.With the author(s)’decision to opt for Open Choice the copyright of the article changed on December 2020 to©“The Author(s)2020”and the article is forth-with distributed under a Creative Commons Attribution 4.0 International License(https://creat iveco mmons.org/licen ses/by/4.0/),which permits use,sharing,adaptation,distribu-tion and reproduction in any medium or format.