甘蔗ATP柠檬酸裂解酶基因的克隆与表达分析

ATP柠檬酸裂解酶(ACL)为细胞质中乙酰辅酶A合成途径的关键调控酶,在生物体正常生长发育中扮演着重要角色。本研究通过Race和电子克隆技术获得编码甘蔗ACL蛋白2个亚基的基因SoACLA-1和SoACLB-1,其编码框长度分别为1 272 bp和1 827 bp,编码423个和608个氨基酸,推测的氨基酸序列与其他物种具有高度相似性,都优先与禾本科植物聚于同一进化分支。2个基因在ATP-grasp功能域、柠檬酸结合位点、组氨酸磷酸化位点和ATP结合、CoA结合、磷酸化区域等,序列高度保守。实时荧光定量PCR结果表明,2个基因均受外源ABA、水分胁迫、水分胁迫加ABA处理诱导表达,且叶中表达量显著高于根系,其中又以水分胁迫处理下的表达量最高,2个基因表现出协同表达模式。SoACLA-1和SoACLB-1的表达与ABA、ROS含量具有相关性,说明它们可能参与了ABA调控的植物对逆境胁迫反应的代谢过程。     

Increase in growth,productivity and nutritional status of rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L. cv. Basmati) and enrichment in soil fertility applied with an organic matrix entrapped urea

Field experiments were conducted to evaluate the effects of eco-friendly organic matrix entrapped urea (OMEU) on growth, productivity, and yield of rice (Oryza sativa L. cv. Basmati) and soil enrichment in the paddy field at Rohtak (Haryana) located near Delhi. The OMEU prepared in granular form contained cow dung, rice bran (grain cover of Oryza sativa), powder of neem leaves (Azadirachta indica), and clay soil (diameter of particles < 0.02 mm) in 1:1:1:1 ratios and saresh (plant gum of Acacia sp.) as binder along with half of the recommended dose of commercially available soluble urea (free urea; FU). Single basal application of OMEU showed an increase in plant growth in terms of fresh and dry weights, root length, root, leaf and tiller numbers, soluble protein, total N and ammonium in leaves, productivity in terms of grain and straw yield, and nutritional and microbial activities of field soil over free form of urea and no fertilizer application. Nutritional status of rice grains was also improved over the free urea and no fertilizer controls. Our data indicate that OMEU, which is low cost and based on bio-degradable, non-toxic, and locally available agro-waste, can be attempted to replace the conventional use of soluble urea in rice.     

GGE biplot analysis to evaluate genotype, environment and their interactions in sorghum multi-location data

Sorghum [Sorghum bicolor (L.) Moench] is a very important crop in the arid and semi-arid tropics of India and African subcontinent. In the process of release of new cultivars using multi-location data major emphasis is being given on the superiority of the new cultivars over the ruling cultivars, while very less importance is being given on the genotype?×?environment interaction (GEI). In the present study, performance of ten Indian hybrids over 12 locations across the rainy seasons of 2008 and 2009 was investigated using GGE biplot analysis. Location attributed higher proportion of the variation in the data (59.3–89.9%), while genotype contributed only 3.9–16.8% of total variation. Genotype?×?location interaction contributed 5.8–25.7% of total variation. We could identify superior hybrids for grain yield, fodder yield and for harvest index using biplot graphical approach effectively. Majority of the testing locations were highly correlated. ‘Which-won-where’ study partitioned the testing locations into three mega-environments: first with eight locations with SPH 1606/1609 as the winning genotypes; second mega-environment encompassed three locations with SPH 1596 as the winning genotype, and last mega-environment represented by only one location with SPH 1603 as the winning genotype. This clearly indicates that though the testing is being conducted in many locations, similar conclusions can be drawn from one or two representatives of each mega-environment. We did not observe any correlation of these mega-environments to their geographical locations. Existence of extensive crossover GEI clearly suggests that efforts are necessary to identify location-specific genotypes over multi-year and -location data for release of hybrids and varieties rather focusing on overall performance of the entries.     

Fijian adolescents’ understanding and evaluation of climate change: Implications for enabling effective future adaptation

Pacific Island countries are particularly vulnerable to future manifestations of climate change due to high coastline‐to‐land‐area ratios, and high dependence of inhabitants on natural ecosystems. While everyone in the Pacific Islands should participate in climate change adaptation activities, it is the young people, given they are the generation likely to not only bear the burden of climate change, but to lead and live effective climate change adaptation activities and strategies specific to their region, the involvement of youth is critical. Pacific Island youths are often marginalised within traditional decision‐making hierarchies, therefore they are typically excluded from participating in meaningful discussions at community and government levels. Discussions were held with 30 adolescents aged 14–18 years in Fiji to explore knowledge and experiences regarding climate change. Participants revealed their dismay at their inability to talk to family – who they consider are not doing enough – about what they consider as appropriate responses to climate change, recommending the help of an authoritative outsider who could speak to their community leaders and family. Discussions also revealed that Fijian youth could not distinguish between changes in the climate and normal weather events, attesting to the importance of climate‐change education and awareness‐raising efforts within the Pacific Islands more generally.     

Mapping of male sterility gene ms10 in chilli pepper (Capsicum annuum L.)

Most of the hybrid seed in chilli are produced manually, but the use of male sterility (MS) can reduce the cost of hybrid seed production. MS‐12, a nuclear male‐sterile (NMS) line developed at Punjab Agricultural University, Ludhiana (India), has been utilized to develop commercial F₁ hybrids. A recessive gene, designated as ms10, governs MS in MS‐12. Due to recessive gene control, development of new NMS lines incorporating ms10 gene is tedious and time‐consuming. We identified SSR markers AVRDC‐PP12 and AVRDC_MD997* linked to the ms10 gene. A total of 558 primer pairs were screened following bulked segregant analysis (BSA). Linkage analysis in 210 F₂ plants indicated that the two SSR markers were linked to the ms10 gene and the marker AVRDC‐PP12 was closest to the gene at 7.2 cM distance. The marker was mapped to chromosome 1 at genome position 175 694 513 to 175 694 644. Until more closely linked markers are developed, the marker AVRDC‐PP12 would facilitate transfer of ms10 gene through marker‐assisted selection (MAS). Fine mapping would lead to cloning of the ms10 gene.     

Cadmium Enhances Generation of Hydrogen Peroxide and Amplifies Activities of Catalase, Peroxidases and Superoxide Dismutase in Maize

Maize (Zea mays L. cv. 777) plants grown in hydroponic culture were treated with 50 μm CdSO₄. Growth and metabolic parameters indicative of oxidative stress and antioxidant responses were studied in leaves of plants treated with Cd. Apart from increasing lipid peroxidation and H₂O₂ accumulation, supply of Cd suppressed growth, fresh and dry mass of plants and decreased the concentrations of chloroplastic pigments. The activities of catalase (CAT; EC 1.11.1.6), peroxidase (POD; EC 1.11.1.7), ascorbate peroxidase (APX; EC 1.11.1.11) and superoxide dismutase (SOD; EC 1.15.1.1) were increased in plants supplied 50 μm Cd. Localization of activities of isoforms of these enzymes (POD, APX and SOD) on native gels also revealed increase in the intensities of pre‐existing bands. Stimulated activities of CAT, POD, APX and SOD in maize plants supplied excess Cd do not appear to have relieved plants from excessive generation of reactive oxygen species (ROS). It is, therefore, concluded that supply of 50 μm Cd induces oxidative stress by increasing production of ROS despite increased antioxidant protection in maize plants.     

Recent advances in molecular marker techniques: Insight into QTL mapping,GWAS and genomic selection in plants

Recent advances in sequencing technology have brought several novel platforms for marker development and subsequent genotyping. The high-throughput and cost effective marker techniques have changed the entire scenario of marker applications. The huge genotypic data obtained with next generation sequencing (NGS) also demands analytical tools, statistical advances, and comprehensive understanding to cope with breeding applications. In the present review, we discussed different available marker techniques, their strengths, and limitations. Emphasis was given on software tools, analytical pipelines, workbenches, and online resources available for marker development. Comparison of SNP genotyping involving complexity reduction techniques like GBS, RRL, RAD, and array-based platforms were presented in a view to describe suitability for specific purposes. We found that genotyping by whole genome re-sequencing has great potential, and could be a routine application in the near future with continuously decreasing cost of sequencing. Microsatellites, still a valuable option for breeders, have also advanced with NGS. Here a catalogue of tools for microsatellite evaluation in short sequence reads was provided. The most common applications of molecular marker like QTL mapping, genome-wide association mapping (GWAS), and genomic selection were highlighted. The present review will be helpful for the effective utilization of available resources and for the planning of crop improvement programs employing molecular marker techniques.     

Aluminium tolerance in lentil (Lens culinaris Medik.) with monogenic inheritance pattern

The objectives of this study were to determine genetics of Al tolerance and whether the Al tolerance observed is governed by the same gene. The lines ‘L‐7903’ and ‘L‐4602’ have been developed through breeding programme as Al‐tolerant lines. These lines showed maximum root regrowth and minimum accumulation of Al and callose as compared to sensitive genotypes (‘BM‐4’ and ‘L‐4147’). Al tolerance in the parents, F₁, F₂ and backcross generations was estimated using the regrowth of the primary root after staining and scoring of fluorescent signals. The F₁ hybrids responded similarly to the tolerant parents, indicating dominance of Al tolerance over sensitivity. The segregation ratios obtained for Al tolerance and sensitivity in the F₂ and backcross generations were 3 : 1 and 1 : 1, respectively. Test of allelism confirmed the same gene was conferring Al tolerance in both genotypes (‘L‐7903’ and ‘L‐4602’) as the F₁ was also tolerant and no segregation of tolerant : sensitive was recorded. These results indicated that Al tolerance is a monogenic dominant trait that can be easily transferred to agronomic bases through backcross breeding technique.