• 한국잠사곤충학회지
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• 제40권1호
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• pp.13-16
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• 1998

From mulberry root bark of 13 various varieties, ${\gamma}$-Aminnobutyric acid(GABA) contents were examined on HPLC analyzer. GABA contents in mulberry root bark were affected by genotypes. Average GABA content of the 13 mulberry varieties was 2.19 mg/gDW. GABA content of the varieties ranged from 1.70 to 2.62 mg/gDW. Among the three genotypes, GABA content of the Morus Lhou was higher than the other genotype. In GABA content Hongolppong was the highest with 2.62 mg/gDW on the 13 varieties of mulberry root bark.

• International Journal of Industrial Entomology and Biomaterials
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• 제8권1호
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• pp.33-41
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• 2004

The type of trichomes, their density and pattern of distribution on leaves of 16 genotypes of mulberry, belonging to both diploid and polyploid categories, were studied by scanning electron microscope. The present investigation was undertaken to find out the relationship of physical attributes, especially the density and trichome types with higher acceptability and better rearing performance by the silkworm Bombyx-mori L. Two types of trichomes glandular and non-glandular types were observed on both the leaf surfaces of all the mulberry genotypes studied. In general, greater densities of trichomes were observed on the abaxial surface than the adaxial surface of leaves in most of the genotypes. Distribution of glandular trichomes were more in abaxial surface and non-glandular trichomes were more in adaxial surface. Overall, distribution of glandular and non-glandular trichomes per unit area of leaf did not follow any regular pattern. When leaves of those genotypes were fed to silkworms, trichome density was found to be significantly negatively correlated with the survival of larvae i.e., effective rate of rearing, but trichome density did not influence the economic characters of rearing. As the distribution of glandular trichomes (GT) and non-glandular trichomes (NGT) did not follow any definite pattern, no relation could be established between the GT and NGT densities with silkworm rearing performance. However, the ratio of GT and NGT in a particular genotype influenced the rearing parameters, higher the ratios better the rearing performance. High GT and NGT ratio (＞1.00) was found positively significant when correlated with economic parameters viz., larval weight, single cocoon weight and single shell weight. The study is useful in screening different mulberry genotypes for their better acceptability to silk-worm and higher rearing performance at the early stage of selection without actually conducting the rearing.

• International Journal of Industrial Entomology and Biomaterials
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• 제4권2호
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• pp.143-147
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• 2002

Studies on the interrelationship between biological yield and harvest index, and their association with shoot rearing were carried out in 9 promising mulberry genotypes, which indicated significant variations among genotypes. Biological yield had close association with leaf yield components indicating that they are inter-related for higher productivity in mulberry, Biological yield revealed highly significant positive correlation with important leaf yield components. However height of the longest branch showed negative correlation with biological yield. Genotypes with higher biological yield associated with low ratio of stem weight to leaf weight and high Harvest index on dry weight basis are to be selected for shoot rearing. Biological yield recorded on fresh weight basis had less impact on the present study in comparison to dry weight basis.

• International Journal of Industrial Entomology and Biomaterials
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• 제6권2호
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• pp.139-143
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• 2003

Mathematical constants for multiplication with leaf length (I) or breadth (b) or l ${\times}$ b have been worked out for determining leaf area in promising mulberry genotypes viz., Chinese White, S-146, Chak Majra and Sujanpur Local of sub-tropical India. When pooled, the mathematical constants worked out were 8.1132, 10.1019 and 0.5992 for multiplication with leaf length, breadth and l ${\times}$ b, respectively, for genotypes bearing un-lobbed leaves and 6.9447, 8.2761 and 0.5009 for multiplication with leaf length, breadth and l ${\times}$ b, respectively for genotypes bearing lobbed leaves. Leaf area can be worked out by using any constant by multiplying either with leaf length or breadth or both (l ${\times}$ b). Estimated leaf areas worked out were found significantly and positively correlated with actual leaf area (r＝999$^{＊＊}$). The suggested present non-destructive method by using mathematical constants is very quick and alternative to electronic leaf area meter for spot leaf area determination in mulberry which is the only food source for mulberry silkworm in sericulture industry.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권2호
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• pp.207-215
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• 2004

The present study was carried out to evaluate the ISSR and RAPD markers for their efficiency as genetic marker systems to establish the relationships between 18 mulberry genotypes. A total of 36 from 56 (64%) RAPD primers and 12 from 48 (25%) ISSR primers produced reproducible amplification patterns. A high proportion of polymorphic bands ranging from 44 to 91% was observed respectively with RAPD and ISSR markers. The average Resolving Power (Rp) of ISSR primers was higher than RAPD primers. The ISSR primers, UBC 825, 868 and 873, and RAPD primers, UBC 712, 720 and 729, possessed the highest Rp values and could in each instance distinguish all the 18 genotypes. Similarity matrix values were estimated based on Jaccards coefficient, considering 109 polymorphic ISSR and 212 polymorphic RAPD bands and two dendrograms were constructed. The dendrograms obtained with ISSR and RAPD markers distinguished the eight exotic genotypes from the ten indigenous (Indian) genotypes. A significant correlation value (r=0.959; p=0.001) for the cophenetic matrix between the RAPD and ISSR matrices was observed. The results indicated that the ISSR and RAPD markers could assist in the differentiation of genotypes and permit the determination of genetic distances that might be exploited by mulberry breeders in improvement programs.

• International Journal of Industrial Entomology and Biomaterials
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• 제41권2호
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• pp.56-62
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• 2020

Mulberry (Morus spp. family: Moraceae) has prime importance in the sericulture industry, and its foliage is the only natural feed of the silkworm Bombyx mori L. Traditional classification methods using morphological traits were largely unsuccessful in assessing the diversity and relationships among different mulberry species because of environmental influences on the traits of interest. For these reasons, it is difficult to differentiate between the varieties and cultivars of Morus spp. In the present study, inter-simple sequence repeat (ISSR) markers were used to investigate the genetic diversity of 48 mulberry samples genotyped using nine ISSR primers. The ISSR markers exhibited polymorphisms (53.2%) among mulberry genotypes. Furthermore, similarity coefficient estimated for these ISSR markers was found to vary between 0.67 and 0.99 for the combined pooled data. The phenogram drawn using the UPGMA cluster method based on combined pooled data of the ISSR markers divided the 48 mulberry genotypes into seven major groups. No genetic association was found in the collection area, and there was a mixed pattern between the mulberry lines. The hybridization between different mulberry species is highly likely to be homogenized due to natural hybridization.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권2호
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• pp.175-182
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• 2002

A new high yielding mulberry genotype, Victory-1 (V-1) was recommended to the field for irrigated areas by Central Sericultural Research and Training Institute (CSRTI), Mysore during 1996-1997. As K-2 and S-36 mulberry genotypes are already in the field, a study on the comparative performance of V-1, 5-36 and K-2 varieties, in terms of leaf yield, yield attributes, leaf moisture and moisture retaining capacity and their impact on silkworm rearing was carried out under Telangana conditions of Andhra Pradesh during 1999-2001. Among the three genotypes the leaf yield was found to be significantly (P < 0.01) higher in V-1 (64,130 kg/ha/yr) followed by S-36 (44,064 kg/ha/yr) and K-2 (23,990 kg/ha/yr). The maximum leaf moisture was also observed in V-1 (71.84%) compared to S-36 (66.86%) and K-2 (64%). The moisture retaining ability was more in V-1 (70.17%) followed by S-36 (66.20%) and K-2 (60.08%). The yield attributes were found to be significantly (P < 0.01) enhanced in V-1 over S-36 and K-2. Silkworm rearing results (bioassay) indicated a significant (P < 0.01) reduction in larval duration and improvement in larval weight, effective rate of rearing by number and weight, single cocoon and shell weights and shell ratio in the silkworm lots fed on V-1 variety followed by S-36 and K-2. Hence, in this study, V-1 was found to be superior among the three varieties studied.

• International Journal of Industrial Entomology and Biomaterials
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• 제5권1호
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• pp.131-134
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• 2002

Mulberry being the only food of silkworm, Bombyx mori L., is of great economic importance to the silk industry, The success in cocoon production mainly depends on the supply of quality leaves in sufficient quantity. In mulberry, where the economic product is leaf, the uptake of nitrogen from soil is very heavy and high responses to application of nutrients have been reported. Nitrogen supports vegetative growth particularly the leaf biomass. Variation in nitrogen harvest index and other physiological and yield contributing traits were estimated in five mulberry genotypes. Considerable variation was observed for nitrogen harvest index, protein yield per plant and harvest index. The correlation studies indicated the protein yield per plant was significantly correlated with leaf yield, nitrogen content in leaf, nitrogen harvest index and harvest index. The broad sense heritability estimates revealed that harvest index showed highest heritability (88.07%) followed by nitrogen content (82.52%), protein yield (70.28%) and nitrogen harvest index (66.52%).

• 한국자원식물학회지
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• 제24권6호
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• pp.675-687
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• 2011

Mulberries have importance in the sericulture industry as food for Bombyx mori, silkworm reared for its silk. Korean Morus alba have many cultivars and, for the protection of these cultivars and for utilization in plant-breeding programs, genetic information and the diversity among cultivars are essential. This study with 14 mulberry genotypes was undertaken using RAPD and ISSR fingerprinting to discover the genetic divergences between cultivars. Polymorphism rate among the cultivars produced by RAPD primer was found to be 64.48% and 66.29% relative to ISSR primer. The genetic relationships among the cultivars were identified using a dendrogram constructed with the UPGMA clustering method. Nei's method was used to calculate the genetic dissimilarity coefficients between each pair of genotypes, and the highest dissimilarity coefficient of 0.246 was exhibited between Suwon and Hwanggum cultivars. To determine the efficiency of each primer, a polymorphic index was calculated, and the robustness of the dendrogram was checked using cophenetic correlation coefficient. The results of this study can be utilized for the improvement of mulberry varieties in plant-breeding programs.

• International Journal of Industrial Entomology and Biomaterials
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• 제10권2호
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• pp.79-86
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• 2005

Molecular markers have increasingly been used in plant genetic analysis, due to their obvious advantages over conventional phenotypic markers, as they are highly polymorphic, more in number, stable across different developmental stages, neutral to selection and least influenced by environmental factors. Among the PCR based marker techniques, ISSR is one of the simplest and widely used techniques, which involves amplification of DNA segment present at an amplifiable distance in between two identical microsatellite repeat regions oriented in opposite direction. Though ISSR markers are dominant like RAPD, they are more stable and reproducible. Because of these properties ISSR markers have recently been found using extensively for finger printing, pohylogenetic analysis, population structure analysis, varietal/line identification, genetic mapping, marker-assisted selection, etc. In mulberry (Morus spp.), ISSR markers were used for analyzing phylogenetic relationship among cultivated varieties, between tropical and temperate mulberry, for solving the vexed problem of identifying taxonomic positions of genotypes, for identifying markers associated with leaf yield attributing characters. As ISSR markers are one of the cheapest and easiest marker systems with high efficiency in generating polymorphism among closely related varieties, they would play a major role in mulberry genome analysis in the future.