Chlorophyl fluorescence transient from initial to maximum fluorescence （“P”step） throughout two intermedi-ate steps （“J”and“I”） （JIP-test） is considered a reliable early quantitative indicator of stress in...Chlorophyl fluorescence transient from initial to maximum fluorescence （“P”step） throughout two intermedi-ate steps （“J”and“I”） （JIP-test） is considered a reliable early quantitative indicator of stress in plants. The JIP-test is particularly useful for crop plants when applied in variable field environments. The aim of the present study was to conduct a quantitative trait loci （QTL） analysis for nine JIP-test parameters in maize during flowering in four field environ-ments differing in weather conditions. QTL analysis and identification of putative candidate genes might help to explain the genetic relationship between photosynthesis and different field scenarios in maize plants. The JIP-test param-eters were analyzed in the intermated B73 ？ Mo17 （IBM） maize population of 205 recombinant inbred lines. A set of 2,178 molecular markers across the whole maize genome was used for QTL analysis revealing 10 significant QTLs for seven JIP-test parameters, of which five were co-localized when combined＆amp;nbsp;over the four environments indicating polygenic inheritance and pleiotropy. Our results demonstrate that QTL analysis of chlorophyl fluorescence parameters was capable of detecting one pleiotropic locus on chromosome 7, coinciding with the gene gst23 that may be associated with efficient photosynthe-sis under different field scenarios.展开更多
The wild type maize genotype, B73, is not amenable for callus production and an efficient protocol for B73 maize callus induction has never been reported up-to-date. Scientific efforts in producing B73 maize callus us...The wild type maize genotype, B73, is not amenable for callus production and an efficient protocol for B73 maize callus induction has never been reported up-to-date. Scientific efforts in producing B73 maize callus using all known callus inducible media have been unsatisfactory. Here we developed and described an efficient protocol for callus induction from B73 maize seedlings. The protocol is based on well known callus inducible media CM4C where we have sequentially subtracted some chemical compounds and added some new compounds mediating cell proliferations. This newly described protocol was able to induce callus production in a wide range of crop species including rice and soybean. We found that cell proliferation factors, NAA (auxin analog) and 2,4 D (auxin influx carrier) were not only very crucial but required for positive B73 maize callus induction. The absence of one or the other will lead to the failure of B73 maize callus production. The well known CM4C callus induction composition lacks NAA. Our findings will advance genetic studies of maize mutants generated from B73 genotype background.展开更多
基金supported by research grants 073-0731674-1673,073-0731674-0841 and 073‐0730463-0203 from Ministry of Science,Education and Sports,Republic of Croatia
文摘Chlorophyl fluorescence transient from initial to maximum fluorescence （“P”step） throughout two intermedi-ate steps （“J”and“I”） （JIP-test） is considered a reliable early quantitative indicator of stress in plants. The JIP-test is particularly useful for crop plants when applied in variable field environments. The aim of the present study was to conduct a quantitative trait loci （QTL） analysis for nine JIP-test parameters in maize during flowering in four field environ-ments differing in weather conditions. QTL analysis and identification of putative candidate genes might help to explain the genetic relationship between photosynthesis and different field scenarios in maize plants. The JIP-test param-eters were analyzed in the intermated B73 ？ Mo17 （IBM） maize population of 205 recombinant inbred lines. A set of 2,178 molecular markers across the whole maize genome was used for QTL analysis revealing 10 significant QTLs for seven JIP-test parameters, of which five were co-localized when combined＆amp;nbsp;over the four environments indicating polygenic inheritance and pleiotropy. Our results demonstrate that QTL analysis of chlorophyl fluorescence parameters was capable of detecting one pleiotropic locus on chromosome 7, coinciding with the gene gst23 that may be associated with efficient photosynthe-sis under different field scenarios.
文摘The wild type maize genotype, B73, is not amenable for callus production and an efficient protocol for B73 maize callus induction has never been reported up-to-date. Scientific efforts in producing B73 maize callus using all known callus inducible media have been unsatisfactory. Here we developed and described an efficient protocol for callus induction from B73 maize seedlings. The protocol is based on well known callus inducible media CM4C where we have sequentially subtracted some chemical compounds and added some new compounds mediating cell proliferations. This newly described protocol was able to induce callus production in a wide range of crop species including rice and soybean. We found that cell proliferation factors, NAA (auxin analog) and 2,4 D (auxin influx carrier) were not only very crucial but required for positive B73 maize callus induction. The absence of one or the other will lead to the failure of B73 maize callus production. The well known CM4C callus induction composition lacks NAA. Our findings will advance genetic studies of maize mutants generated from B73 genotype background.
