Transgenic Nicotiana tabacum plants expressing RNA sequences of the tomato spotted wilt virus NS(M) gene, which encodes the putative viral movement protein, were found to be highly resistant to infection with the virus. Expression of untranslatable as well as anti-sense RNA of the NS(M) gene resulted in resistance levels as high as those in plants expressing translatable RNA sequences. For all three types of transgenic plants resistance levels of up to 100% were reached in the S2 progeny. These results indicate that the resistance mediated by the NS(M) gene is accomplished by expression of transcripts rather than protein in transgenic plants, similar to previously observed N gene-mediated resistance. Protoplast inoculations revealed that resistant plants expressing NS(M) are, in contrast to N transgenic resistant plants, not resistant at the cellular level. This suggests the RNA-mediated resistance mechanism against TSWV targets viral mRNAs rather than the viral genome.
This study was aimed to isolate and identify a gene that was responsive to drought stress in sugar cane variety M442-51, a variety that is widely used in pastures or dry land. Under drought stress, M442-51 showed an enhance expression of several proteins. One of the protein, namely dip22, (drought inducible protein, with a molecular weight of 22KDa) was isolated and analyzed. Amino acid sequence of this protein showed some homology with several stressed related proteins (OsAsr 1 from Oryza sativa leaves, ZM Bss1 of Zea mays leaves, LeAsr 1, LeAsr 2 and LeAsr 3 of Lycopersicum lycopersicon leaves). The 343 bp of dip22-cDNA fragment was obtained using RT PCR from mRNA of sugar cane leaves that has been exposed to drought stress. The results indicated that the gene dip22 plays an important role as a regulatory protein that are usually nested within cytoplasmic matrix or in the nucleus.
Mandheling coffee has been a well known specialty coffees for decades and the demand for this coffee is currently increasing. This coffee is characterised by low acidity, heavy-complex body, spicy-little earthy and fruity flavor. Mandheling coffee is produced by smallholder farmers in the highland surrounding Lake TobaNorth Sumatra in an unique way i.e. following de-pulping and 1–2 days sundrying, wet parchment is stored for varying periods up to a few weeks, the parchments are then de-hulled when still wet (40–45% moisture content) then the beans sundried. The handling procedure presumably contributes to the unique cup character of Mandheling coffee. On the other hand the storage of wet pachments may cause mould growth and mycotoxin contamination. This trial was designed to study the influence of storage of wet parchments prior to wet hulling on mould development, OTA contamination and cup Mandheling characteristic of the coffee product. The normal wet process, drying of parchment thoroughly to 12% moisture content was used as the control. Parchment coffees (6 lots) used for this trial were drawn from farmers and collectors in the region. The wet parchments (41.74–53.96% moisture content) were stored for 1 (D1), 7 (D7) and 14 (D14) days in PE sacks in a warehouse in the region. During the storage period, when there was visible mould growth, the parchments were spread on a plastic sheet inside the warehouse, as per common practice to suppress the mould growth. Following storage, the wet parchment was de-hulled and then sun-dried to a moisture content of 12% (MC12%) or dried to a moisture content of 17%, and held in storage for 3 weeks prior to final drying to 12% mc. The ‘normal wet process’ i.e. fresh-non stored parchments dried thoroughly to 12%, were used as the control. Parameters measured were visual evaluation, mould infestation, a w, moisture content (MC) on the stored parchment; while for dried beans mould infestation, OTA content and the Mandheling cup character evaluation (done by 4 panelists who were familiar to the coffee) were determined. Some mould species grew during the storage course, with black Aspergillus was the dominant species found in the beans, while A. ochraceusan OTA producer, was found in some samples with low infection rate (0–15.3%). Spreading of coffee inside the warehouse during the day could suppress moulds growth. OTA was found in only 5 samples out of 42 samples with range of 0.17–2.24 ppb, very less than European Union limit. There was no clear trend of storage period on the mould infection rates, OTA content, and the Mandheling cup characters. The high variability of the outcome was likely due to the inhomogenity of parchments used for this trial. The best Mandheling was found in the sample of D1-MC12%-coffee source of lot 1. Key words: Mandheling coffee, storage, wet parchment, mould, ochratoxin A.
Coffee storage was an active process, where the quality and flavor was depend on the origin, humidity, temperature, period, and ware house condition. The objective of this research was to know quality and flavor of some Arabica coffee varieties in interval of storage periods. The examined coffee varieties were BP 416 A, BP 430 A, BP 432 A, BP 509 A, BP 542 A, P 88, AS 1, S 795, and USDA-762. The treatments were recent harvest, one and two years stored green coffee. The green coffee were wet processed, sun dried, packed in polyethylene bags, one kg/pack and placed in some covered plastic boxes. The boxes were stored in ware house covered with wavy asbes roof and flat asbes ceiling. The green coffee was examined for its moisture content, color, and bulk density. The green coffee was roasted at medium level, and then examined for its the bulk density, yield, volume of swelling, and color of the roasted and powdered. The flavors examination was blind test method. The research showed that storage period significantly influenced the moisture content, color, and bulk density of green coffee, yield, volume of swelling, color of roasted coffee, color, and flavor profile of coffee powder. Those varieties tested showed significantly different on the moisture content, green coffee color, roasted coffee color, coffee powder color, and the profile flavor. The storage period influenced the green coffee color from greenish-gray to yellowish-red. The bulk density of green coffee decreased. The varieties that showed a little color changeduring storage, were BP 430 A,BP 416 A, AS 1, and S 795. One year of storage periode, the green coffee was still had the original color, but after two years, the original color had changed totally. The powder of recent harvest coffee was darker than that of one and two years storage. One year stored coffee had higher quality of aroma, intensity of aroma, quality of flavor, intensity of flavor, acidity, quality of after taste, intensity of after taste and preference, than the recent harvest and two years stored coffee. recent harvest had higher body, bitterness, and astringency, than that of one and two years stored coffee. The main off-flavor of recent harvest coffee was green and grassy, the one year stored coffee was harsh, woody, earthy, and sour, while the two years stored coffee was harsh, woody, earthy and moldy. The flavor change in the first year was higher than in the second year storage. The varieties, that had lowest change on flavor during storage, were BP 416 A, AS 1, P 88, BP 432 A and S 795. Key words: Coffee, Arabica, variety, clone, storage, quality, flavor, color.
Somatic embryogenesis is a technique to produce primary embryos using tissue culture. Contamination in tissue culture can be caused by internal and external contaminant. Resterilization can be performed to save contaminated embryos. The aim of this research is to obtain resterilization method in cocoa micropropagation by tissue culture so that free bacterial explants can be obtained and embryogenic. This experiments used five clones of cocoa, namely Sulawesi 1, KW 514, ICCRI 05, ICCRI 03 and ICCRI 04. Embryogenic clusters in multiplication medium were used as explant. Sodium hypochloride was used as sterilant. Several factors were evaluated using randomized block complete design, i.e. contaminant level, concentration of sterilant and period of sterilant application. Results of resterilization methods showed no significant effect among several factors tested. Among those factors, low contamination level, 10% concentra tion of sterilant and no soaking showed the highest percentage of saving of contaminated embryos. There was different response among five cocoa clones in producing embryogenic explants when using combination of resterilization methods. Key words : Theobroma cacao, somatic embryogenesis, contamination, resterilization.
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