Artan Dozlarda Magnezyum Sülfat Uygulamalarının Tütün Bitkisinin Yaprak Verimi ve Kalitesine Etkisi

This research was carried out to determine the effects of fertilizers with MgSO4 applied in the increasing amounts (0, 3, 6 and 9 kg da-1) on the leaf yield, leaf quality and some chemical (Mg, S, N, P, K, nicotine, sugar, chlorogenic and rutin concentration) parameters of tobacco in the field conditions of Tokat/Erbaa and Tokat/Kazova locations in 2017 year. The research was established in three replications according to the randomized block design, and the leaves that reached the harvest maturity were harvested in three hands. According to the results, with increasing doses of MgSO4 application, there was an increase in the leaf yield of the tobacco cultivar grown in Erbaa and Kazova locations. The increase in leaf yield was seen at the dose of 6 kg da-1 of MgSO4 and this increase was 22% in Erbaa location and 6.4% in Kazova location. It was observed that increasing MgSO4 applications caused statistically significant increases in leaf Mg and S concentrations, and the highest increase was observed in the leaf yield at a dose of 6 kg da-1. Nicotine concentration, which is a very important alkaloid component for tobacco, caused a decrease in both locations with MgSO4 application. The results revealed that increasing doses of MgSO4 caused an increase in the yield of tobacco leaves, an increase in leaf Mg and S concentrations, and a decrease in nicotine concentrations.

Lycopene β-cyclase expression influences plant physiology, development and metabolism in tobacco plants

Carotenoids are important isoprenoids produced in the plastids of photosynthetic organisms that play key roles in photoprotection and antioxidative processes. β-carotene is generated from lycopene by the lycopene β-cyclase (LCYB). Previously, we demonstrated that the introduction of the Daucus carota (carrot) DcLCYB1 gene into tobacco (cultivar Xanthi) resulted in increased levels of abscisic acid (ABA) and especially gibberellins (GAs), resulting in increased plant yield. In order to understand this phenomenon prior exporting this genetic strategy to crops, we generated tobacco (cultivar Petit Havana) mutants that exhibited a wide range of LCYB expression. Transplastomic plants expressing DcLCYB1 at high levels showed a wild-type-like growth, even though their pigment content was increased, and their leaf GA content was reduced. RNAi NtLCYB lines showed different reductions in NtLCYB transcript abundance, correlating with reduced pigment content and plant variegation. Photosynthesis (leaf absorptance, Fv/Fm, and ETRII) and plant growth were impaired. Remarkably, drastic changes in phytohormone content also occurred in the RNAi lines. However, external application of phytohormones was not sufficient to rescue their phenotypes, suggesting that altered photosynthetic efficiency might be another important factor explaining their reduced biomass. These results show that LCYB expression influences plant biomass by different mechanisms and suggests thresholds for LCYB expression levels that might be beneficial/detrimental for plant growth.

Leaf area estimation of Burley tobacco

ABSTRACT: Leaf area is an important growth variable in agricultural crops and the leaf is the main variable of interest in the tobacco industry. So, the aim of this scientific research was to estimate the Burley tobacco leaf area by linear dimensions of the leaves and to determine which mathematical model is more adequate for this purpose. Two experiments were carried out with Burley tobacco, cultivar DBH 2252, in 2016/2017 and 2018/2019 agricultural years, respectively, in the municipalities of Itaqui and Vanini - RS - Brazil. In 600 leaves were measured length (L), width (W), length×width product (LW), length/width ratio (L/W) and determined the real leaf area (LA). Four hundred and fifty leaves were separated to generate models of the leaf area as a function of linear dimension and the other 150 leaves were used for model’s validation. The power model LA = 0.5037LW1.04435 (R² = 0.9960) is the most adequate for Burley tobacco ‘DBH 2252’ leaf area estimation. Alternatively, the models LA=2.0369W1.8619 (R²=0.9796) and LA=0.1222L2.2771 (R²=0.9738) based on width and length, respectively, can be used when only one leaf dimension is measured.

Discrimination of tobacco cultivars using SCAR and RAPD markers

Tobacco genetic purity is crucial to maintain the quality of cigarette products in the tobacco industry. To reduce the difficulties in the discrimination of large number of tobacco cultivars in production practice, we developed a two-step identification strategy by using SCAR and RAPD markers. A total of 53 tobacco cultivars were examined in the study. Initially, all the selected cultivars were divided into four groups, each group consisted of seven to seventeen tobacco cultivars based on difference in phenotypes identified by the SCAR markers S4 and S8. Later, in each group, each tobacco cultivar was identified using RAPD fingerprinting by using one to four polymorphic primers, which were selected from 200 random primers. The results showed that all 53 tobacco cultivars could be effectively distinguished by using only two SCAR and seven RAPD markers. The two-step fingerprinting strategy could be used as a convenient and cost-effective tool to discriminate large numbers of tobacco cultivars for production planning in the tobacco industry.

ISOLASI FRAGMEN GEN PENYANDI PUTRESIN N-METILTRANSFERASE DAN QUINOLINAT FOSFORIBOSILTRANSFERASE ASAL TEMBAKAU LOKAL TEMANGGUNG (Nicotiana tabacum)

<p>ABSTRAK</p><p>Upaya untuk menurunkan kandungan nikotin merupakan salah satuprioritas utama penelitian tembakau. Nikotin adalah senyawa alkaloidutama berpotensi dikonversi menjadi senyawa nor-nikotin yang bersifatkarsinogen. Gen PMT sebagai penyandi enzim putresin n-metiltransferase(PMT) dan gen QPT - penyandi enzim quinolinat fosforibosiltransferase(QPT) merupakan dua gen kunci yang berperan penting pada proses bio-sintesis nikotin. Penelitian ini bertujuan untuk mengisolasi potongan genPMT dan QPT asal tembakau lokal Indonesia, mengkarakterisasi danmenganalisis runutan DNA-nya. Tahapan penelitian dimulai dengan me-rancang primer degenerate berdasarkan informasi yang ada di pangkalandata Bank Gen NCBI (National Centre for Biotechnology Information),mengamplifikasi PCR menggunakan templat DNA genomik tembakaulokal cv. Sindoro1, mengklon potongan DNA hasil PCR dan menentukanrunutan DNA-nya. Hasil penelitian menunjukkan dari dua belas pasangprimer degenerate yang dirancang, hanya dua pasang primer yang meng-hasilkan potongan DNA hasil amplifikasi PCR, yaitu pasangan primerPMt-7 (F &amp; R) untuk gen PMT dan primer QPt-3 (F &amp; R) untuk gen QPT.Setelah dilakukan penentuan runutan DNA-nya, amplikon yang didapatdari hasil PCR dengan pasangan primer PMt-7 sebesar 1418 bp, sedangkanuntuk primer QPt-3 sebesar 205 bp. Runutan DNA gen PMT dan gen QPTasal tembakau lokal cv. Sindoro1 mempunyai tingkat kesamaan yang ting-gi dengan gen PMT dan gen QPT asal tembakau lainnya yang ada dipangkalan data Bank Gen NCBI.</p><p>Kata kunci : Gen PMT, gen QPT, lintasan biosintesis nikotin, perunutanDNA, amplifikasi PCR, primer degenerate</p><p>ABSTRACT</p><p>Isolation of Genes encoding Putrescine N-Methyl-transferase and Quinolinat Phosphoribosyl transferasederived from Temanggung Tobacco Cultivar (Nicotianatabacum)</p><p>Reduction of nicotine content is one of the major objective intobacco research. Nicotine is the main alcaloid compound that potentiallycould be converted into a carcinogenic compound (nor-nicotine). The PMTgene encoding putrescine N-methyl transferase (PMT) and the QPT gene -encoding quinolinate phosphoribosyl transferase (QPT) are the two keyenzymes involved in nicotine biosynthesis. The objectives of this researchwere to isolate PMT and QPT gene fragments originated from Indonesianlocal tobacco, to characterize, and to analyze their DNA sequences. Theresearch activities included: degenerate primer design based oninformation available in the GenBank DNA Database NCBI (NationalCentre for Biotechnology Information), PCR amplification usingdegenerate primer and genomic DNA template of a local tobacco cv.Sindoro1, clone the PCR amplified products, and determine their DNAnucleotide sequences. Results of the experiment indicated that from 12degenerate primer pairs synthesized, only two were able to yield positivePCR amplified products. These primer pairs were PMt-7 (F &amp; R primers)for PMT and QPt-3 (F &amp; R primers) for QPT. After DNA sequencing, theamplified DNA product amplified using PMt-7 degenerate primer pairswere 1418 bp, while that using QPt-3 primer pairs were only 205 bp.Nucleotide sequences of PMT or QPT gene fragments originated fromlocal tobacco cv. Sindoro1 showed a high nucleotide sequences identity ascompared to that of the respective genes from other tobacco species thatwere available in the GenBank DNA Database NCBI.</p><p>Key words: PMT gene, QPT gene, nicotine biosynthetic pathways, DNAsequencing, PCR amplification, degenerate primer</p>

Genetic Control of Facultative Parthenocarpy in Nicotiana tabacum L.

Investigation of parthenocarpy, the production of fruit without fertilization, in multiple plant species could result in development of technologies for conferring seedless fruits and increased stability of fruit formation in economically important plants. We studied parthenocarpy in the model species Nicotiana tabacum L., and observed variability for expression of the trait among diverse genetic materials. Parthenocarpy was found to be partially dominant, and a single major quantitative trait locus on linkage group 22 was found to control the trait in a doubled haploid mapping population derived from a cross between parthenocarpic cigar tobacco cultivar “Beinhart 1000” and nonparthenocarpic flue-cured tobacco cultivar, “Hicks.” The same genomic region was found to be involved with control of the trait in the important flue-cured tobacco cultivar, “K326.” We also investigated the potential for the production of maternal haploids due to parthenogenesis in parthenocarpic tobacco seed capsules. Maternal haploids were not observed in parthenocarpic capsules, suggesting a requirement of fertilization for maternal haploid production due to parthenogenesis in N. tabacum.

The Tobacco Trichome Exudate Z-abienol and Its Relationship With Plant Resistance to Phytophthora nicotianae

In previous research, we discovered a favorable quantitative trait locus (QTL) in cigar tobacco cultivar ‘Beinhart 1000’ designated as Phn15.1, which provides a high level of partial resistance to the black shank disease caused by Phytophthora nicotianae. A very close genetic association was also found between Phn15.1 and the ability to biosynthesize Z-abienol, a labdanoid diterpene exuded by the trichomes onto above-ground plant parts, and that imparts flavor and aroma characteristics to Oriental and some cigar tobacco types. Because accumulation of Z-abienol is considered to be undesirable for cultivars of other tobacco types, we herein describe a series of experiments to gain insight on whether this close association is due to genetic linkage or pleiotropy. First, in an in vitro bioassay, we observed Z-abienol and related diterpenes to inhibit hyphal growth of P. nicotianae at concentrations between 0.01 and 100 ppm. Secondly, we field-tested transgenic versions of Beinhart 1000 carrying RNAi constructs for downregulating NtCPS2 or NtABS, two genes involved in the biosynthesis of Z-abienol. Thirdly, we also field tested a recombinant inbred line population segregating for a truncation mutation in NtCPS2 leading to an interrupted Z-abienol pathway. We observed no correlation between field resistance to P. nicotianae and the ability to accumulate Z-abienol in either the transgenic materials or the mapping population. Results suggest that, although Z-abienol may affect P. nicotianae when applied at high concentrations in in vitro assays, the compound has little effect on black shank disease development under natural field conditions. Thus, it should be possible to disassociate Phn15.1-mediated black shank resistance identified in cigar tobacco cultivar Beinhart 1000 from the ability to accumulate Z-abienol, an undesirable secondary metabolite for burley and flue-cured tobacco cultivars.