Sheikh Shorif Uddin Ahmed

This study investigated the effects of polyethylene glycol (PEG)-induced osmotic stress on the germination and seedling growth of five tossa jute varieties under three treatment conditions: control, PEG 5%, and PEG 10%. Significant reductions were observed in germination percentage (GP), seedling length and fresh and dry weight of root and shoot under PEG treatments. Total length (TL), root length (RL) and shoot length (SL) were reduced under PEG stress, particularly in varieties Acc. 1148(V2) and Acc.6099(V3). PEG reduced mean GP from 94.4% (control) to 87.1% (PEG 5%) and 88.8% (PEG 10%), and reduced mean shoot length by 16–24%, while root length was largely maintained or increased, indicating a shift in early biomass allocation under osmotic stress. BJRI Tossa pat 5(V4) consistently showed the highest tolerance to PEG stress, maintaining relatively better germination, seedling growth, root length and biomass compared to other varieties. Correlation study revealed that, early seedling vigor in tossa jute is strongly influenced by root length, root biomass and total dry matter accumulation. The positive associations between GP, TL and RW highlight their importance as selection indices for drought tolerance while negative correlations of shoot weight with root traits indicate an adaptive balance between root and shoot under water deficit. BJRI Tossa pat 5 was identified as a promising genotype for early-stage drought tolerance but subsequent validation is needed under field water-deficit conditions.

Tossa jute (Corchorus olitorius L.) is a natural fibre crop that produces good quality golden fibre. Predicting fibre yield and quality is crucial in jute breeding programs. Fibre anatomical characteristics provide valuable insights into both fibre yield and quality. Hence, seven tossa jute genotypes were investigated through field-based morphological studies and laboratory-oriented anatomical studies for fibre yield and yield-attributing morpho anatomical variability at Bangladesh Jute Research Institute (BJRI) during March 2023 to February 2024. Morphological analysis revealed significant genotypic variations in plant height, base diameter, green weight, fibre yield and stick yield (p < 0.05), highlighting their potential as key differentiators for breeding activities. The genotypes JRO-524 and O-0412-9-4 exhibited superior traits, including higher plant height (2.67 m and 2.64 m) and base diameter (13.89 mm and 13.18 mm) at 110 days after sowing. High heritability was observed for green weight (80.22 %) and fibre yield (80.05 %), indicating that these traits can be effectively targeted for genetic improvement. Anatomical studies revealed significant variability in stem diameter, bark thickness and fibre bundle attributes (p < 0.01). JRO-524 demonstrated the highest stem diameter (17.67 mm) and bark thickness (1.53 mm), while BJRI Tossa pat 9 excelled in trapezoid width and total bundle area. Principal component analysis (PCA) captured 85.7 % of cumulative variance across the first three components, with plant height, base diameter and fibre yield being major contributors. The PCA biplot categorized genotypes into five groups, elucidating genetic diversity for targeted breeding strategies. These findings will provide a foundation for developing high-yielding, fibre-rich tossa jute varieties in future.

Waterlogging is a serious abiotic stress for Tossa jute cultivation in flood-prone areas or haor areas of Bangladesh. There is no waterlog-tolerant variety in Bangladesh, and hence it is essential to study the growth performance of Tossa jute genotypes under waterlogged stress. Two previously selected lines, Accession (Acc.) 1306 and Acc. 1318, an exotic variety JRO-524 and three popular varieties, e.g., BJRI Tossa pat 5, BJRI Tossa pat 8 and BJRI Tossa pat 9, were grown at Jute Agricultural Experiment Station, Manikganj in 2022. Jute genotypes were grown in three different blocks in which two plots were inundated at 65- and 80-day age, respectively and one plot was used as a control without inundation. Artificially, waterlog condition was maintained for 30 days. Survivability status and other agronomic characteristics (plant height, stem diameter, fresh weight, root length, fiber yield) were observed closely after the submergence condition. There was a difference in the plant survivability percentage. Maximum plants (97.1%) of Acc. 1306 were survived under waterlog conditions at 65 days after sowing (DAS) but in case of inundation at 80 DAS, JRO-524 had maximum survivability (92.9%) than other genotypes followed by Acc. 1318(91.6%) and BJRI Tossa pat 8 (90.2%) Among all jute genotypes, BJRI Tossa pat 5 gave highest fiber yield (3.05 t/ha) when inundated after 80 days followed by inundated after 65 days (2.75 t/ha) in this variety compared to the control. Correlation study reveals that fiber yield and stick yield of Tossa jute are strongly correlated; root length and adventitious root length have negative correlation with green weight with leaf, fiber and stick yield. BJRI Tossa pat 5 showed robust adaptive responses with notable increases in both root length and adventitious root length in case of inundation at 65 and 80 DAS. BJRI Tossa pat 5 may be considered as a relatively waterlog tolerant Tossa jute variety which can be used for cultivation in flood-prone areas of Bangladesh.

Salinity is a serious abiotic stress to Jute and other crop cultivation at saline regions in the world. No salt tolerant Tossa Jute (Corchorus olitorius L.) variety was developed in Bangladesh. Hence, six Tossa Jute accessions were investigated at germination stage against six concentration levels (0.00 or d.H2O, 8.0, 10.0, 12.0, 14.0 and 16.0 dS m-1) of salt (NaCl) using RCB design at Bangladesh Jute Research Institute (BJRI) during March-July, 2020. Jute seeds collected from Gene Bank of BJRI were allowed to germinate under laboratory condition. Seed germination rate was adversely affected as well as delay in germination was prolonged with increasing the salt concentration. In control, seeds were germinated up to 14.0 dS m-1 salt solution. Among six genotypes, Acc. 1141 and Acc. 3801 showed the highest germination rate (86.67 %); Acc. 3801 gave maximum root length (17.0 mm), dry biomass (6.37 mg); and Acc. 1089 showed higher shoot length (10.0 mm), fresh weight (43.93 mg) and salt tolerance index (60.69 %) under 14.0 dS m-1 level. Higher relative salt harm rate (7.14 %) was observed in both Acc. 1141 and Acc. 3801 under 14.0 dS m-1 salinity indicating highly tolerance to salinity. Acc. 3801 and Acc. 1141 were found good for germination under salt stresses; Acc. 3801, Acc. 1089 for fiber yield and salt tolerance; Acc. 3801 and Acc. 1407 for higher fiber yield. Acc. 3801 was found good for salt tolerance and fiber yield content. The genotypes with good desirable characters would be used as breeding materials to develop high yielding salt tolerant Tossa Jute variety.