• International Journal of Industrial Entomology and Biomaterials
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• v.7 no.1
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• pp.15-20
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• 2003

The present investigation was carried out to study the possible cause for reciprocal difference in silkworm hybrids. By utilising the polyvoltine race Pure Mysore (PM) and newly evolved breeds (CSR2, CSR5, CSR16 and CSR17), the direct and reciprocal crosses of polyvoltine ${\times}$ bivoltine and also bivoltine hybrids were studied. The hybrids of polyvoltine ${\times}$ bivoltine (direct) are superior to their reciprocal crosses in respect of cocoon yield, cocoon weight and filament length. The reciprocal crosses of polyvoltine ${\times}$ bivoltine are superior to their direct crosses in respect of fecundity and short larval duration. No significant differences were observed in the characters like cocoon shell ratio, raw silk percentage, denier, reelability and neatness in both polyvoltine ${\times}$ bivoltine direct crosses and their reciprocals. The expression of cocoon characters as a function of sex revealed that direct crosses (polyvoltine ${\times}$ bivoltine) showed higher cocoon weight, pupal weight, shell weight and longer filament length in females than the reciprocal crosses (bivoltine ${\times}$ polyvoltine), where as these characters in males were almost the same in both direct and reciprocal crosses, indicating that the sex-linked genetic factor played a more important role. it was clear that difference in cocoon yield observed in reciprocal crosses of polyvoltine ${\times}$ bivoltine was due to the low cocoon and shell weight in females which was turn due to presence of early maturity genes (Lme) linked with sex-chromosome (X) which effect on larvae period of the silkworm. In bivoltine hybrids, i.e., both direct and their reciprocals crosses, all the characters viz., hatching percentage, larval duration, survival, cocoon weight, cocoon shell weight, cocoon shell ratio, raw silk percentage, filament length, denier, reelability and neatness did not show any significant difference (except number of eggs laid by moth) which could account for presence of same maturity genes (Lm) in both direct and reciprocal crosses. it was clear that reciprocal differences occur when the hybrids are prepared from the parental strains with different voltinism.

• Communications for Statistical Applications and Methods
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• v.8 no.2
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• pp.367-374
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• 2001

In this paper, a method based on group divisible designs is presented for constructing some partial diallel crosses. We discuss in detail a particular inbred line, i.e., p lines divided into two groups with p$_1$ lines and p$_2$ lines. These designs are obtained by regarding the number of lines as treatments. In specially we study and compare the efficiency factors of the constructed partial diallel crosses with or without repeated blocks.

• Communications for Statistical Applications and Methods
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• v.9 no.2
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• pp.435-441
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• 2002

In this paper, orthogonal block designs for partial diallel crosses are proposed. These partial diallel crosses block designs for estimating general combining abilities are constructed by using $\alpha$-resolvable partially balanced incomplete block designs. Also, the efficiencies of the partial diallel crosses block designs obtained through this method are reported in table.

• Communications for Statistical Applications and Methods
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• v.9 no.1
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• pp.33-38
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• 2002

We prove that blocked complete dialler crosses using balance incomplete block design are A-, D-, E-optimal design. Also, we provide such blocked complete dialled crosses and their average efficiency with table.

• Proceedings of the Korean Statistical Society Conference
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• 2001.11a
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• pp.121-124
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• 2001

In this paper, partial diallel crosses designs are proposed. These designs for estimating general combining abilities are constructed by using m-associate class partially balanced incomplete block designs. Also, the efficiency of the partially diallel crosses designs obtained through this method is reported in table.

• Communications for Statistical Applications and Methods
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• v.9 no.2
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• pp.443-450
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• 2002

In this paper, block designs for control versus test comparisons among the lines for diallel crosses are proposed. These block designs are constructed by using balanced incomplete block designs. Also, the efficiencies of the diallel crosses block designs obtained through this method are tabulated for number of lines 23 or less.

• Communications for Statistical Applications and Methods
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• v.9 no.2
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• pp.337-346
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• 2002

Complete diallel crosses using group divisible design with m=2 or n=2 and ${\lambda}_1$<${\lambda}_2$ as parameter designs become A-optimal, D-optimal designs. In case of ${\lambda}_2$=${\lambda}_1$+1, this blocked complete diallel crosses become generalized optimal designs.

• The Korean Journal of Applied Statistics
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• v.15 no.2
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• pp.367-379
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• 2002

In this paper, the method of constructing incomplete block designs for comparing general combining abilities of p inbred lines for partial diallel crosses is proposed. These partial diallel crosses block designs are constructed by using m-associate class partially balanced incomplete block designs with block size 2 and balanced incomplete block designs. Also, the efficiencies of block designs obtained through this method are tabulated for number of lines 24 or less.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.113-126
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• 2012

Northern corn leaf blight caused by Exserohilum turcicum Pass is considered the most important disease infecting corn (Zea mays L.) in the Peoples' Republic of Korea (North Korea). It contributes to the food shortage in North Korea. The objectives of the current research were to study resistance expression and responses of corn crosses made between ten hybrids from North Korea and inbreeding lines ($S_{3-4}$ stage) from the Republic of Korea (South Korea). The experiments were conducted in six trials with a total of 184 crosses including two commercial hybrids in each trial. The trials were conducted at two locations in North Korea (Mirim and Eunsan) and one location in South Korea (Gunwi) under natural infestation of E. turcicum. Host plant responses were rated on a scale of 1 (highly tolerant) to 9 (highly susceptible). A total of 111 crosses (62.4%) showed significant tolerant or susceptible response variations among three locations; 42 crosses (22.8%) at two locations and 69 crosses (39.0%) at one location, respectively. At least 8 crosses of high level of tolerance and 12 crosses of high level of susceptibility showed significantly different biotic responses (P = 0.05). The results of the current study and historical reviews of E. turcicum epidemics in both North and South Korea suggest that breeding of tolerance with quantitatively inherited genes should be carried out for a sustainable corn production in North Korea.

• Communications for Statistical Applications and Methods
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• v.9 no.3
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• pp.733-741
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• 2002

A class of block designs for general combining ability comparisons within two groups of inbred lines in diallel crosses is given. These block designs are constructed by using balanced block designs obtained by cyclically developing a single initial block. Also, the efficiencies of block designs are tabulated for number of lines 26 or less.