Characterization of dhaincha accessions based on morphological descriptors and biomass production
Forty five accessions of dhaincha germplasms were collected from different parts of Bangladesh and characterized on the basis of morphological descriptors and biomass production ability. Thirty eight accessions were identified as Sesbania bispinosa, four as S. cannabina and two as unidentified Sesbania spp. One accession as S. rostrata was included for comparison. Both at seedling and maturity stages, wide and significant differences were observed among the accessions of different dhaincha germplasms for their biomass production capability and other morphological descriptors. At the seedling stage, total dry mass (TDM) production varied from 10.2 to 41.6g 30-plants–1. At the maturity stage, plant height, total number of branches and base diameter of dhaincha germplasms varied from 347.5–474.7cm, 10.4–23.7, and 1.9–4.9cm, respectively. The highest amount (4.10kg 10-plants–1) of above-ground TDM was produced in one accession of unidentified Sesbania sp. followed by S. rostrata and one accession of S. cannabina (3.85kg 10-plants–1), and the lowest TDM (0.9kg 10-plants–1) was measured in two accessions of S. bispinosa. It may be concluded that the biomass production capability of at least two accessions of local Sesbania germplasms were higher/comparable to that of exotic S. rostrata. It will be too early to make a conclusive remark based on only a few dhaincha germplasms. A detailed study with a large number of germplasms collected from whole Bangladesh is obviously needed to reach in a precise conclusion.
Screening of Sesbania accessions based on seed germination and seedling biomass
Quality seed is the prime source of good crop production and human needs, the ultimate goal of food and nutritional security. Seeds quality is a rather broad term and encompasses several factors: seed viability, seed health, varietal and physical purity, germination, however, the further essential factor is the more mysterious trait of seed vigour (Finch-Savage and Bassel, 2016). Seed viability, emergence and germination (%) can affect the optimal plant population in the field; and lack of seedling vigour in surviving plants cannot achieve the maximum biomass yield and yield components of crops (Dornbos, 1995).Vigorous seeds germinate easily, establish rapidly and plants may be uniform in favorable environmental conditions (Finch-Savage and Bassel, 2016). Seedling survival or establishment depends on root growth potential; shoot-root ratio, nutrients status of soil and it’s availability to plant as well as environmental conditions (Larsen et al., 1986). Moreover, high vigorous seeds should be used in all instances to ensure good standard establishment under field condition. Seed emergence, germination and seedling vigour has a vast domain feature of genetic purity and seed longevity; however, they may contribute to some differentiation in seedling growth like plant height, base diameter, and root and shoot development as lead to biomass yield (Rezapour et al., 2013). All these yield contributing descriptors will enhance total biomass production of a crop in the field. If the germination percentage is lower than its optimum value then total biomass production will be lower (Srivastava and Kumar, 2013). The unavailability of quality seeds is one of the major constraints of the popularization of green manure crops in Bangladesh. Commercially available seeds of green manure crops commonly show lower seed germination (%) as well as seedling vigour (Dhaka et al., 2014). Three indigenous species of Sesbania viz. S. sesban (L.) Merr., S. bispinosa (Jacq.) W. Wight ORIGINAL RESEARCH ARTICLE Archives of Agriculture and Environmental Science 3(2): 137-142 (2018) https://doi.org/10.26832/24566632.2018.030206
APPLICATION OF SATELLITE PHOTOGRAPHS IN A MORPHOTECTONIC STUDY OF THE CENTRAL ALBORZ, IRAN
This paper introduces a study of morphotectoni c structure in the Central Alborz Basin, Mazandaran province of Iran (about 1200 square kilometer), using Russian KFA-1000 satellite photography and sequential air photographs. The KFA-1000 metric camera has better ground resolution than SPOT and LANDSAT for the whole of the study area. Results are provided from one pair of 30×30 cm. photos, which provided easy interpretation and better results than other data. Areas identified from these images as being of significance were examined in greater detail through the use of aerial photographs (at scales of 1:5000, 1:10000 and 1:60000 were available).