American Journal of Science

Key words:
technical parameters, correlation coefficient, 
viability, economic valuable properties, silkworm, cocoons yield, 
industrial hybrid, life duration, female-moth, selection signs. 
1. Introduction
The decree of the President of the Republic of Uzbekistan №2856 of 
March 29, 2017 “About measures on organization of Uzbekipaksanoat 
association activity” plays an important role in guaranteeing the system 
perspectives. In accordance with this decree, “Uzbekipaksanoat 
association and enterprises, entering to its structure must be engaged in 
preparing of qualitative silkworm seeds, in increasing of manufacture 
capacity of ready-made silk products and bringing them to the level 
answering the requirements of world market. 
2.
Main part.
Highly productive, percent cocoon shell and high technical parameters of 
silkworm strains and hybrids have great significance in production of 
qualitative, competitive (marketable) and high-yielding cocoons. If to 
create and inculcate breeds and commercial hybrids suitable to each 
region, then this serves as the base for production of qualitative cocoons 
yield. New scientifically based methods of selection and pedigree works 
play significant role in creation of new highly-productive, possessing by 
high viability breeds. 
Such signs as productivity, viability, reproduction more deeply 
studied among selection signs. But silkworm life duration nearly haven’t 
explored. Scientific research of property’s changeability, significant and 
interesting from selection point of view and interrelation with leading 
economically valuable signs is an actual scientific direction of silkworm 
selection at present. 
In our research it was clear the following fact that defining 
silkworm female-moth life duration and by using interrelation of this 

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American Journal of Science 
index with other signs in selection and seed breeding works, the quality of 
producing elite and commercial hybrid seeds can be improved. 
For the first time it was defined in our research work the degree of 
inter correlative relation of changeability coefficient of silkworm female-
moth life duration with productivity and viability signs. Obtained 
scientific results having great significance for the theory of genetics and 
silkworm selection gave possibility for the usage of effective assorting 
methods in conducting of selection works on creation of new races and 
hybrids.It is known that it is necessary to conduct selection process of 
silkworm on proper methods not only in scientific-research works, but in 
family nurseries on pure-strain breeding on super elite and elite stages. 
That’s why obtained scientific results on female-moth life duration can be 
used in selection measures performing on creation new high yielding, 
highly viable races, and also in family nurseries of pedigree 
farms.N.G.Badalov [1] studied changeability degree of silkworm 
reproductive characteristic in his research works. In works of 
N.G.Bagautdinov, N.V.Polyanskaua, K.N.Yaroslavtzeva [2] data on the 
influence of ultra-red rays on moth emergence from purebred cocoons and 
increasing the number of qualitative eggs in a laying were 
given.V.I.Kireeva, M.G.Linnik, L.K.Malchenko, N.T.Ostapenko [3] 
suggested to cross zoned races White cocoon 1 and White cocoon 2 at 
elite stage with the purpose of enlargement of cocoons yield, obtaining 
from purebred silkworm breeding and improvement of seed quality 
receiving from them.V.A.Strunnikov [4] comprehensively explored the 
appearance of sexual cells in moth body and the possibility of regulation 
of impregnation process was proved. U.N.Nasirillaev [5] recommended 
to use male-moths several times at silkworm breeding farms and creation 
an opportunity to increase selection differential at the expense of 
employment this process into practice till 2-4 times was noted.We can 
mention 
works 
of 
S.Ya.Demyanovskiy, 
V.A.Rozhdestvenskaya, 
E.I.Stakhovskaya 
[6], 
O.N.Memedniyazov, 
M.N.Shulika 
[7], 
T.T.Tuchkova [8], A.M.Muzaffarov, T.T.Taubaev, U.N.Nasirillaev, 
Kh.F.Yakubov, I.Elmurodova [9] among research works devoted to this 
theme. 
It is necessary to remember some conclusions made on the base of 
large-scale deep scientific research works of E.Mikhaylov, E.F.Poyazkov, 
before analyzing life duration of silkworm female-moths. On statement of 

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American Journal of Science 
these great scientist-researchers healthy moths after laying eggs can live 
from 1-2 days to 20-25 days depending on keeping conditions. 
Such state also find prove in our research. That is some moths of 
Marvarid and Line-27 races were alive till 27days. These authors, basing 
on the results of their experiments and biochemical analysis, defined, that 
the reason of moth’s natural death is the intoxication distribution in the 
organism as a result of protein molecule destruction in the cells of healthy 
moths. If in the organism accumulate sufficient amount of protein 
consequently the influence of great quantity of toxins to the organism is 
strong and sensible.
One of the main aims of our research work is the definition of the 
degree of interrelation between female-moth’s life duration and leading 
economic valuable traits. Inter correlative relations of economic valuable 
signs during selection and pedigree works have great importance. Because 
it is necessary that selection work conducting on a certain feature must not 
lead to the reduction of the other second feature. Besides, knowledge of 
directions of important signs inter-relations in making of selection 
program and also right definition of assorting methods can give great 
effect. 
In the connection with this we tried to determine the degree of inter 
correlative relations between characteristics of life duration and 
productivity, viability of female-moths of two sharply differing from each 
other breeds Marvarid and Line-27. 
For this in 2015 female-moths of races were divided into 3 types of 
groups-gradations according to life duration: 
To the 1-st gradation the longest lived moths (16-24 days); 
To the 2-nd gradation medium lived moths (9-11 days); 
To the 3-rd gradation the less lived moths (5-6 days) were entered. 
Eggs laying, which was defined as healthy, on the results of microanalysis 
according these gradations, were unified and the mixture was prepared.
In spring 2016 gradations were separately incubated and hatched 
(insects rearing started). Hatched silkworms were reared, cocoons were 
obtained and their weight and percent cocoons shell were estimated. Then 
cocoons technological parameters were determined and average index of 
all signs on gradations were calculated. 
Phenotypic correlation coefficient between average index of moths 
life duration defined on gradation and characteristics of viability, 

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American Journal of Science 
productivity was determined. Obtained indices of correlation coefficient 
were shown in table-1.