PhD M.V. Shilina,* PhD H.M. Maltanava**

Vitebsk state Unirversity named after P.M.Masherov c. Vitebsk*

Belorussian state Unirversity c. Minsk**

The influence of environment factors on the genetic control of the attributes of producing capacity of a tomato. Part 1.

Introduction

There is in the structure of phenotypic variation of quantitative attributes specific place takes the interaction between the genotype and environment. The defined physiological and genetic mechanisms of adaptability is said with respect to specific adaptability or stability to stressful influence the factor of environment in zone of taxonomic extremum and subextremum (frost-, heat-, drought-, salt -resistance etc.). Nowadays there are the biochemical mechanisms of transcriptional variability are investigated (methylation of cytosine, acetylation of histones). It is discovered molecules of RNA which determine posttranscriptional regulation of activity of gens.

The epigene character have been the genotype-environmental effects, which connect with modification expression in the process of ontogenesis and the forming cenosis without fixation these effects in breed. The one and the same feature shows the different QML in different conditions. The selection methods of resistance, which use now, are labour-intensive. It is perspective to develop identifications of molecular markers of resistance to stress. For example, there are stability mRNA of phytochrome or presence bihedrins. Bihedrins are the one of protein’s group, that is accumulated in answer to the different stress factors ( a low temperature, a osmotic stress, a treatment by abscisic acid. It has been snown, that bihedrins are peripheral membranous proteins, which act as stabilizers of membranes at the different water and saline stresses. The functions of many proteins aren’t researched, that why selectionists use the classic method of phenotype selection of valuable genotype.

Experimental.

It has been studied the character of inheritance of trait “contain the dry substance in fruits” during two years against a background the different nitrogen's provision.

As parent’ strains were used the sorts Petomech and Meridian, which differ from each other by the important traits. It has been analyzed the first and the second generations (F₁, F₂) as well as their reciprocal hybrids BCP₁ and BCP₂. As the control was chosen the background of the soil N₁₈₀P₁₈₀ (NO₃ in the soil was up-to-date 40-70 mg/kg dry soil; P₂O₅ – 40-60 mg/kg dry soil; K₂O – 300-400 mg/kg dry soil). As a factor of the stress was chosen the background with high nitrogen’s content N₅₄₀P₁₈₀ (NO₃ in the soil was 150 – 400 mg/kg dry soil). It has been estimated the content dry substance in fruits (10 fruits from each 14 plants of every samples). Agrotechnics was generally accepted.

Results and discussion.

The special program “Genetic monitoring” was created for mathematical treatment of the data which allowed discovering allelic and nonallelic interactions in the genetic control of treats. It could determine the effect of the environment in inheritance of trait. The method of K. Mather, J. L. Jinks is the basis for investigation.

The basic purpose of this method is selecting the simulator (tests A, B, C), which minimize the interactions between the genotype and the environment. It will probably remove the effects of the nonallelic interactions.

It has been introduced the parameters m, [d] and [h] for explanation the all variation between the middle values of hybrids by the allelic interaction. Observed and expected values have been compared at Pirson criterion χ². If χ² is significant we can suppose a presence of the epistatic effects. The next parameters [i], [j], [l] have been introduced to determine the type of the epistatic effects. The weighting coefficients (1/S_i)² have been searched out for every values Р₁, Р₂, F₁, F₂, ВСР₁ and ВСР₂.

We received six equations with six unknown quantities.

The system of the equations have been whiten in the matrix form:

I*M=S, where I is information matrix, М is a vector of valuations of parameters (which must be found), S is matrix observed values. The received systems of linear equations have been solved by the method of Gauss-Jordano. Algorithm of realization this method foresees the check of absence of degeneracy of the matrix I.

The contrastive analysis has been carried with help graphs expected and observed values.

The interaction for pair locus may be classify on basis of two criteria.

1. The conformity of sign of parameter [h] by signs [i] and [l]. The presence once combination of signs these parameters indicates to the complementarity or recessive epistatic effect, the others show to duplicate genes or dominant epistatic effect.

2. The correlation between quantities and signs [d] and [h]. For example, if these different parameters at the quantity and signs, we may distinguish complementarity and recessive epistatic effect and duplicate genes and dominant epistatic effect.

Conclusions.

The interaction between genotype and environment in control of the treat content dry substance in fruits was significant against a background increased nitrogen provision. It wasn’t significant against a background control during two years. Hence, selection of the best phenotype samples is recommended to exclude at the given treat against background increased content nitrogen in soil as where are revealed environmental and nonallelic interactions. The conformity by additive-dominate model and positive heterosis have been determined against a background the control. It has been given the possibility to recommend parent forms as a donor of this treat.