Papers by Md Sazzadur Rahman
Bangladesh Journal of Agricultural Research, 2010
A study was conducted during Boro and T. Aman seasons of 2002 at Bangladesh Rice Research Institu... more A study was conducted during Boro and T. Aman seasons of 2002 at Bangladesh Rice Research Institute (BRRI), Gazipur to see the relationship of SPAD (Soil plant analysis development) reading with chlorophyll and N contents of leaves and to determine the critical LCC value for rice crops. Hybrid varieties Sonarbangla-1 and BRRI hybrid dhan0l were used for both rice crops and BRRI dhan29 and BRRI dhan31 were used as checks for Boro and T. Aman crops, respectively. Sonarbangla-1, BRRI hybrid dhan0l and BRRI dhan29 had similar leaf chlorophyll contents in Boro season. The maximum chlorophyll content (1.6-1.8 mg/g leaf) was observed at 39-42 soil plant analysis development (SPAD) value. In T. Aman season, the inbred BRRI dhan3l showed lower amount of chlorophyll (1.2-1.4 mg/g leaf) at 39-42 SPAD value compared to the hybrids Sonarbangla-1 and BRRI hybrid dhan 0l. Seasonal variation in chlorophyll content between Sonarbangla-1 and BRRI hybrid dhan0l was not large. Relationship between SPAD...
Scientific Reports, 2019
The rice landrace Horkuch, endemic to the southern saline coast of Bangladesh, is known to have s... more The rice landrace Horkuch, endemic to the southern saline coast of Bangladesh, is known to have salt tolerance traits and can therefore contribute to a high yielding recipient for breeding purposes. In this study, we reciprocally crossed Horkuch with high yielding but salt sensitive IR29 to detect the complement of genes that were responsible for conferring salt tolerance versus sensitivity at the seedling developmental stage. We looked at tolerant and sensitive F 3 families from individual F 2 segregating plants and analyzed them for differential gene expressions using RNAseq. In general, we observed higher numbers of genes differentially expressed in leaves compared to root tissues. This included both upregulation and downregulation of gene expression across our experimental factors. Gene expression decreased in sensitive leaf after stress exposure where tolerant plants showed the opposite trend. In root, tolerant plants expression decreased at higher time points of stress exposure. We also observed a strong maternal cytoplasmic effect on gene expression and this was most evident in roots where there was upregulation in functional enrichments related to phosphorylation, electron carriers, transporter and cation transmembrane activities. Stress groups (tolerant and sensitive) response in F 3 families were distinctive in both cytoplasmic backgrounds and involved uniquely upregulated genes in tolerant progenies including membrane sensor proteins, enzymes involved with signaling pathways, such as those producing trehalose and G-protein coupled receptor proteins, photosynthesis-related enzymes and golgi body recycling as well as prolamin precursor proteins involved in refolding of proteins. On the other hand, sensitivity was found to be associated with differential upregulation of only a few redox proteins and higher number of apoptosis related genes compared to the tolerant response. Overall, our highly replicated experimental design was powerful and allowed the detection of relatively subtle differential expression. Our future goal is to correlate these expression differences with QTLs in this population, which would help identify the relative importance of specific genetic loci and provide a direct avenue for combining higher levels of salt tolerance with better agronomic traits in rice. Nearly 1 million ha of coastal soil in Bangladesh or nearly a ninth of the total cultivable area is affected by soil salinity, mostly due to seawater intrusion 1. The inhibitory levels of salinity for rice cultivation (>4 dS/m) are seasonal, except in certain pockets of the South West 2. During the dry season water levels are usually low due to upper riparian withdrawal as well as its overexploitation, causing a build-up of salts. However, these coastal areas are home to many salt tolerant rice landraces, including both indica and aromatic subgroups, which have allelic diversity at several genetic loci associated with tolerance from donor landraces like Pokkali and Nona Bokra 3,4. One of these rice landraces, Horkuch, was previously characterized as salt tolerant at the seedling stage 3,5 and at the reproductive stage 6. These rice landraces from coastal Bangladesh are likely to harbor novel sources of salt tolerance, due to their allelic diversity, that can complement known salt tolerance genes. The introduction of
… Rice Research Notes, 2005
Germination of seeds while on the parent plant before harvest is referred to as preharvest sprout... more Germination of seeds while on the parent plant before harvest is referred to as preharvest sprout-ing. Preharvest sprouting of seeds in the panicle is a common prob-lem where rain and flash flood frequently occur and plants lodge because of gusty winds and when ...
Bangladesh Journal of Botany, 2010
Twenty seven anther culture lines (AC-lines) from rice (Oryza sativa L.) were produced from salin... more Twenty seven anther culture lines (AC-lines) from rice (Oryza sativa L.) were produced from saline tolerant F 2 progeny after crosses between salt tolerant IRRI-derived lines and Bangladesh Rice and advanced up to Double Haploid 3 (DH 3) generation. Similarly crossed material, which did not respond to anther culture, was also advanced up to F 7. The AC-lines were fully characterized for various salinity tolerance parameters at seedling and reduction division stages. The breeding lines were selected for tolerance again at F 4 and advanced on site in the coastal area. DH 3 plants were also evaluated for agronomic performance in normal soil. The best performing breeding as well as AC-lines in terms of salinity tolerance and agronomic properties were planted in farmers fields in the Boro season, when salinity levels are the highest in the coastal zones of Satkhira. One anther derived line AC-1 and three breeding lines, BR7076, BR7077 and BR7098 produced high yield under stress conditions, whereas AC-1, BR7076 and BR7077 showed moderate reduction in grain yield compared to non-saline conditions. Considering both tolerance and yield performance in the saline area, AC-1 showed more stability compared to the breeding lines.
ABSTRACT Swertia chirata is an indigenous medicinal plant of temperate Himalaya which has been wi... more ABSTRACT Swertia chirata is an indigenous medicinal plant of temperate Himalaya which has been widely used in erbal and folk medicine. The study aimed to evaluate the phenolic content, antioxidant and andiabetic potential of . chirata in different solvents. The edible portion (stem) of the plant was extracted with distilled water and different concentrations of methanol, ethanol and acetone to determine total phenolic content (TPC), ntioxidant properties by ferric reducing antioxidant power (FRAP), total antioxidant capacity (TAC), DPPH free radical scavenging activities and antidiabetic property by inhibition of %-amylase. All the extracts showed antioxidant and antidiabetic properties although they varied significantly (P<0.05) among the different extractions. TPC varied between 20 ± 2 mg GAE/100g (ethanol 100%) to 221 ± 12 mg GAE/100g (water extracts), FRAP ranged between 18 ± 4 mg AAE/100g (acetone 100%) to 162 ± 4 mg AAE/100g (water extracts) and TAC ranged between 139 ± 17 mg AAE/100g (acetone 100%) to 707 ± 71 mg AAE/100g (acetone 50%). DPPH radical scavenging and alpha amylase inhibition activities were determined in dose dependent manner ranging between 3-15 mg/mL and 7-21 mg/mL respectively. Acetone 50% showed the most prominent dose dependent scavenging of DPPH radical while alpha amylase inhibition by ethanol 100%, methanol 100% and acetone 100% were comparable with each other. The study revealed the influence of solvent extraction on phenolic compound, antioxidant and %-amylase inhibition activities of S. chirata. These findings support the use of the plant as a traditional and folk medicine.
Plant Systematics and Evolution, 2014
ABSTRACT Haridhan rice was discovered by a farmer in his field which was planted with the widely ... more ABSTRACT Haridhan rice was discovered by a farmer in his field which was planted with the widely cultivated mega-rice BR11. He noticed Haridhan’s variant characters compared to BR11, saved the seeds, planted it in 4–5 successive generations and noted the increase in yield with low input in fertilizer. Due to the overall similarity between BR11 and Haridhan, breeders were unwilling to call the latter a different genotype. This study was therefore performed to investigate the genetic similarity between BR11 and Haridhan. Polymorphism between Haridhan and BR11 using 115 SSR markers was 25 %, close to the reported 11 % for essentially derived (EDV) maize inbred lines. Similarly, 40 RAPD and 1,536 SNP markers showed polymorphism to be 16 % and 5 %, respectively. SSR polymorphic loci between the two were absent in chr 4, 6 and 9 but present in variable numbers in the rest. Some of the embedded and highly polymorphic SSRs were found in the 5′UTR of regulatory genes like Ser–Thr protein kinase and evolutionarily conserved C-terminal protein and revealed a common motif for binding TRA2-BETA1, a Serine–Arginine-rich protein involved in regulating and selecting splice sites. Genetic distance based on the Dice coefficient between Haridhan and BR11 as well as the cultivars, Lal Swarna and Guti Swarna planted in neighboring fields is 0.24, 0.26 and 0.20, respectively, compared to an average of 0.03 for EDV’s like maize inbred lines. Therefore, Haridhan could possibly have been derived from a cross of BR11 with another BR11 having outcrossed genes from the rice cultivars Lal Swarna and Guti Swarna.
Molecular Breeding, 2012
To improve the salinity tolerance of rice, a DEAD-box helicase gene isolated from pea with a CaMV... more To improve the salinity tolerance of rice, a DEAD-box helicase gene isolated from pea with a CaMV35S promoter was transformed into the Bangladeshi rice variety Binnatoa through Agrobacterium-mediated transformation. The transgenic seedlings showed significantly higher chlorophyll content, but decreased root length compared to wild type (WT) under normal physiological conditions. Their status was confirmed by polymerase chain reaction (PCR), semi-quantitative reverse-transcription PCR and Southern blot hybridization for positive integration of the transgene. The T 2 progenies from three independent transformation events were characterized for salinity tolerance both at seedling and reproductive stages. Compared to the WT plants, the average decrease in chlorophyll content and dry weight of seedling leaves was lower by 20 and 12% respectively at 12 deciSiemens per meter (dS/m) NaCl stress in hydroponics. A higher leaf K ? /Na ? ratio of 0.346 was maintained by the transgenic lines compared to the WT ratio of 0.157, which indicated induced ion homeostasis. At the reproductive stage, transgenic rice plants expressing PDH45 showed better fertility and produced higher grain yield by 16% compared to WT plants under continuous stress of 6 dS/m from 30 days till maturity. One of the transformed lines, PDH45-P3, outperformed the others, and replicated data in reproductive stage soil stress of 12 dS/m NaCl showed its enhanced fertility and yield by 46 and 29% over WT, respectively.
… Rice Research Notes, 2005
Germination of seeds while on the parent plant before harvest is referred to as preharvest sprout... more Germination of seeds while on the parent plant before harvest is referred to as preharvest sprout-ing. Preharvest sprouting of seeds in the panicle is a common prob-lem where rain and flash flood frequently occur and plants lodge because of gusty winds and when ...
Bangladesh Journal of Botany, 2008
Laboratory experiments were conducted to study the effect of salt solution, and size and ageing o... more Laboratory experiments were conducted to study the effect of salt solution, and size and ageing of seeds on growth efficiency of rice seedlings. Variation in growth efficiency due to different factors was significant. Seeds of Pokkali, BRRI dhan 29, BRRI dhan 40 and BRRI dhan 41 rice genotypes were used. Growth efficiency and other seedling characteristics decreased as salinity levels increased. Three varieties of rice BR 14, BRRI dhan 28 and BR 1, which are large, medium and small grain variety, respectively, were used to study the effect of seed size on growth efficiency and seedling growth. All the parameters decreased remarkably with decreasing seed size. Seed size influenced the growth efficiency significantly. For accelerated ageing test five varieties of freshly harvested seeds were used. The tested varieties responded differently for growth efficiency. When the ageing treatments were extended to 72 hours the growth efficiency depressed markedly for most of the varieties. Key...
The efficiency of hybrid rice seed production can be improved by increasing the percentage of exs... more The efficiency of hybrid rice seed production can be improved by increasing the percentage of exserted stigmas. To identify quantitative trait loci (QTLs) for this trait, we conducted QTL mapping using 75 chromosome segment substitution lines (CSSLs) developed from a cross between the donor parent, Xieqingzao B (XQZB), a maintainer line which has high stigma exsertion and the recurrent parent, Zhonghui 9308 (ZH9308), a restorer line which has low stigma exsertion. A total of nine QTLs (qSSE5, qSSE10, qSSE11, qDSE10, qDSE11, qTSE5, qTSE6, qTSE10, and qTSE11) for single stigma exsertion (SSE), dual stigma exsertion (DSE) and total stigma exsertion (TSE) were assessed in two environments (Hainan and Zhejiang). Six of these QTLs (qSSE10, qSSE11, qDSE10, qDSE11, qTSE10 and qTSE11) were found in both environments , while one QTL (qTSE6) was found in only Hainan, and two QTLs (qSSE5 and qTSE5) were found in only Zhejiang. The qSSE10, qSSE11, qDSE10, qDSE11, qTSE6, qTSE10 and qTSE11 alleles, which are derived from the parent XQZB, exhibited a positive additive effect. In contrast, the qSSE5 and qTSE5 alleles, which are derived from the parent ZH9308, exhibited a negative additive effect. The SSE, DSE and TSE traits were significantly correlated with each other in an environmentally dependent manner. These results indicated that the lines showing higher values for SSE were more likely to exhibit increased values for DSE, which would ultimately increase TSE. To evaluate the advantage of exserted stigmas for cross-pollination, single, dual and total stigma exsertion should be considered separately in future attempts at genetic improvement to achieve increased production of rice hybrid seeds. This study also provides information for fine mapping, gene cloning and particularly marker assisted selection (MAS), on the latter and with an emphasis the phenotypic effects and implications of the QTLs for practical use in hybrid rice breeding.
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Papers by Md Sazzadur Rahman