• International Journal of Industrial Entomology and Biomaterials
• /
• 제20권2호
• /
• pp.61-67
• /
• 2010

The bivoltine tropical tasar ecoraces of Antheraea mylitta Drury produces cocoons for seed production under seed crop rearing (July-August with $22{\sim}30^{\circ}C$ temperature and 50~70% relative humidity) and for silk production under commercial crop rearing (September-December with $17{\sim}27^{\circ}C$ temperature and 60~80% relative humidity). To consider the impact of hybrid vigour on egg, larva, cocoon and silk related commercial traits, the $F_1$ hybrids made among Daba, Jata and Raily ecoraces were assessed successively for three years. The hybrid vigour in the $F_1$ hybrid of Daba$\times$Jata ($T_7$) was positive for egg fertility (+23.1%), shell weight (+25.6%), silk yield (+79.0%) and filament length (+68.1%), with filament of high denier (11.98d) and reduced larval span (-7.1%). The Jata$\times$Daba ($T_8$) hybrid has shown negative heterosis in egg fertility (-8.0%) compared to the other F1 hybrids, Daba$\times$Raily ($T_9$) and Raily$\times$Daba ($T_{10}$), when they rise simultaneously during the commercial crop season. The better performance of parental ecoraces ($T_4$ to $T_6$) in their commercial traits during commercial crop over parents of seed crop ($T_1$ to $T_3$) and the superior performance of $F_1$ hybrids ($T_7$ to $T_{10}$) over parents of commercial crop ($T_4$ to $T_6$) during commercial crop season indicates the apparent hybrid vigour in tasar $F_1$ hybrids. As the Daba$\times$Jata ($T_7$) and Jata$\times$Daba ($T_8$) $F_1$ hybrids have shown highest hybrid vigour, their rearing during commercial crop can optimize the silk productivity and commercial sustenance of the tasar silk industry.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제4권1호
• /
• pp.37-41
• /
• 2002

Heterosis studies on rearing performance of 25 Fl Polyvoltine $\times$ bivoltine (sex-limited cocoon colour) hybrids revealed that manifestation of heterosis was highly significant for majority of the economic traits contributing to more silk yield. Five hybrids namely BL24${\times}$ CSR 19 (SL), BL24${\times}$${\times}$${\times}$${\times}$${\times}$

• Animal cells and systems
• /
• 제9권2호
• /
• pp.75-78
• /
• 2005

Fungicides and antagonists were tested for their efficacy in the management of fungal pathogens of watermelon. The fungal species in different genera were isolated from the seeds of watermelon and their vulnerability was assessed against an array of chemicals and bioagents. Among the fungal pathogens, Fusarium species were effectively controlled by Bavistin. Topsin also showed the promising effects against all the fungal pathogens, and Dithane M-45 effectively controlled Didymella bryoniae. Seed treatment with antagonists like Trichoderma harzianum and T. viride improved the seed germination, seedling vigour and reduced the incidence of seed-borne fungal pathogens. Bavistin and Topsin among chemicals increased significantly the seed germination and vigour index. Trichoderma harzianum showed its efficacy against all Fusarium species and even stood effective than Captan and Blitox. However, Pseudomonas fIuorescens also showed promising effect against Didymella bryoniae over fungicides. Under field condition, Topsin and Dithane M-45 showed better yield than Bioagents.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2001년도 춘계 학술대회지
• /
• pp.226-227
• /
• 2001

• International Journal of Industrial Entomology and Biomaterials
• /
• 제7권1호
• /
• pp.59-63
• /
• 2003

In the present study, hybrid vigour in terms of heterosis and over dominance of newly evolved bivoltine hybrids and their reciprocals raised from the promising newly evolved bivoltine breeds were calculated for the important parameters like pupation, cocoon yield, cocoon weight, shell weight, shell ratio, raw silk percentage, filament length and neatness. Through there was no significant difference among the hybrids for the characters pupation, cocoon yield and cocoon weight, the magnitude of heterosis and over dominance were varied significantly for these characters. However, significant differences were observed between new hybrids and control hybrid for the characters like cocoon shell weight, cocoon shell ratio, filament length and raw silk percentage. The results indicate that majority of new hybrids have shown higher heterosis and over dominance than control hybrid. The data also indicate that highest mean heterosis of all new hybrids was recorded for cocoon yield followed by filament length. Whereas highest mean over dominance was recorded for cocoon yield followed by cocoon weight. Negative mean heterosis and over dominance were recorded for the trait cocoon shell ratio. Based on the results, the importance of three hybrids viz., CSR2 ${\times}$ CSR4, CSR2 ${\times}$ CSR5 and CSR3 ${\times}$ CSR6 and their reciprocals (CSR4 ${\times}$ CSR2, CSR5 ${\times}$ CSR2 and CSR6 ${\times}$ CSR3) which exhibited significant heterosis and over dominance, for commercial exploitation was discussed.

• Journal of Forest and Environmental Science
• /
• 제38권4호
• /
• pp.256-262
• /
• 2022

The timing of seed harvesting is an important decision in the management of seed orchards because it affects seed quality and yield. To investigate the effect of cone harvest time on seed quality and determine the optimal harvesting time, cones were regularly collected in seven times and germination tests were performed at each harvest time in two clonal seed orchards of Chamaecyparis obtusa. As cones developed, the percentage of seed germination increased before cone moisture content began to decrease significantly. The moisture contents of cones were highest at the first collection as 68.3% and 67.3% in Jeju and Gochang seed orchards respectively. At this time, germination speed was slowest, indicating poor seed vigour. The highest germination was found at the second stage in Jeju (36.5%) and at the seventh stage in Gochang (28.6%) seed orchard. The germination speed increased as cone moisture content decreased. Additionally, changes of seed vigour differed among the developmental stages in both seed orchards. Consequently, the optimal cone harvest time of C. obtusa seed orchards in Jeju was early September when high germination percentage was obtained. In Gochang seed orchards, late October was optimal cone harvest time when the germination speed was fast and the cone moisture content decreased.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제7권2호
• /
• pp.209-219
• /
• 2003

An experiment was initiated to evaluate hybrid vigour in twelve F$_1$ hybrids and seven three-way crosses of multivoltine ${\times}$ bivoltine silkworm between newly evolved multivoltine breed BL67 with productive bivoltine CSR breeds and hybrids. Analysis of variances computed for different characters among F$_1$hybrids and three-way crosses showed highly significant differences among them indicating presence of both additive and non-additive gene actions for the expression of these characters. Among twelve F$_1$ hybrids, two F$_1$ hybrids viz., BL67${\times}$CSR$_4$and BL67${\times}$CSR$_{5}$ have expressed significant heterosis for nine characters and two hybrids viz., BL67${\times}$NB$_4$D$_2$and PM${\times}$NB$_4$D$_2$ for eight characters whereas out of nine three-way crosses, three hybrids viz., BL67${\times}$ (CSR$_3$${\times}$CSR$_{6}$), BL67${\times}$(CSR$_{16}$${\times}$CRS$_{17}$) and BL67${\times}$(CSR$_{18}$ ${\times}$CSR$_{19}$) expressed significant heterosis for eight characters. In the present study, it is observed that the cocoons of two hybrids viz., BL67${\times}$CSR$_4$and BL67${\times}$CSR$_{19}$ were found to be uniform as these hybrids showed lowest CV％ (5.35 and 5.38) among twelve F$_1$ hybrids and seven three way crosses between multivoltine ${\times}$ bivoltine hybrids. Four F$_1$ hybrids viz., BL67${\times}$CSR$_4$, BL67${\times}$CSR$_{5}$, BL67${\times}$ (CSR$_3$${\times}$CSR$_{6}$), BL67${\times}$(CSR$_{16}$${\times}$CRS$_{17}$) and BL67${\times}$(CSR$_{18}$ ${\times}$CSR$_{19}$) showed superiority in expressing hybrid vigour and are considered as best heterotic hybrids for commercial exploitation.ion.ation.ion.ation.ion.

• 한국초지조사료학회지
• /
• 제23권4호
• /
• pp.277-282
• /
• 2003

신개간 산지토양을 공시배지로 한 pot 시험으로 초지조성비 3요소 중 인산비료인 중과석과 용성인비의 시비가 초지조성 초기단계에서 목초의 초기생육, 식생비율 및 수량에 미치는 영향을 비교$.$검토하였다. 처리수준은 1) T$_1$, 대조구, 3요소 표준 시비량의 10% 시비, T$_2$; 중과석 시비, T$_3$; 용성인비 시비이였다. 1. 신개간 산지토양의 화학성은 매우 불량하였다. 목초의 초기생육(달관조사；1∼9등급: 1= 매우 양호, 9=매우 불량)은 T$_2$=2.0＞T$_3$=3.0＞T$_1$=8.0 순으로 3요소 시비가 불충분한 T$_1$(대조구)은 매우 불량하였고, 중과석(T$_2$) 시비는 용성인비(T$_3$)보다 더 양호하였다. 2 상대수량(T$_2$수량=100,0% 기준)을 비교하여 보면 T$_3$은 orchardgrass가 87.7%, white clover 는 76.8%, 이들의 혼파목초는 83.3%로 낮았다. 혼파목초의 수량은 일반적으로 white clover의 수량변화 특성과 비슷한 경향을 보였다 3. 척박한 신개간 산지토양에서 초지조성 시초기 정착단계에서는 목초의 초기생육 및 수량에 미치는 영향은 중과석이 용성인비 보다 더 양호하였고 white clover가 orchardgrass 보다 상대적으로 더 크게 영향을 받았다. 그러나 예취 후반으로 갈수록 white clover의 식생/수량비율이 T$_3$에서 23.7% \$\longrightarrow$ 33.9 \$\longrightarrow$ 47.9%로 증가하는 특성을 고려할 때 초지 관리비 시용에서는 용성인비가 더 긍정적인 효과를 보일 것으로 생각되었다.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2019년도 추계학술대회
• /
• pp.205-205
• /
• 2019

• International Journal of Industrial Entomology and Biomaterials
• /
• 제9권1호
• /
• pp.41-46
• /
• 2004

A breeding programme was initiated by utilizing a robust bivoltine breed CSR$_{18}$ and a polyvoltine breed Cambodge with the main objective of developing robust polyvoltine silkworm breeds/hybrids. At F$_1$ and F$_2$, parthenogenetic development was induced following warm water treatment of eggs at 46$^{\circ}C$ for 18 min followed by two backcrosses with Bl$_{67}$, an evolved polyvoltine breed. The newly developed breed was subjected for hybrid study using eight hybrid combinations in the laboratory at F$_{8}$ generation. F$_1$ hybrids between newly developed breed Bl$_{67}$ (Pg) and promising bivoltine breeds exhibited their superiority by expressing significant hybrid vigour for several economic characters like cocoon yield/10,000 larvae, cocoon weight, cocoon shell weight, cocoon shell ratio and denier. Study on cocoon shape variability revealed that cocoons of all the F$_1$ hybrids except BL$_{67}$ (Pg)${\times}$NB$_4$D$_2$ were found comparatively uniform in shape.pe.