Selection of early ripe eggplant varieties resistant to root-knot nematodes

. The article presents the results of many years of research with the aim of creating eggplant varieties and hybrids with early valuable economic traits and traits resistant to root-knot nematode. In the breeding nursery, 3 second-generation eggplant hybrids (F2), obtained as a result of generational research in 2005-2013, were studied. The lines were characterized by growth period, early ripening, fruit weight, shape, color, plant type, etc. At the end of the growing season, the lines were dug up, assessed for damage by root nematodes and selected for the root system. As a result of the research, 16 early ripening lines were identified with high productivity and quality of fruits, resistant to nematodes and other economically valuable traits. In particular, the early, high-yielding, nematode-resistant line L-32-3 was transferred to the State Variety Test in 2021 under the name Globus variety.


Introduction
Eggplant, which is one of the valuable vegetable crops, has been grown in large numbers by farmers and farms of our republic in greenhouses, under film covers, as a repeated crop after grain.
Currently, the productivity of eggplant is high, the amount of dry matter in the fruit is high, the fruit is tasty, has the quality of confectionery, the taste is not bitter, the seeds in the fruit are few, and it is resistant to diseases and pests.
There is a lot of information in the literature about the use of natural environments in the evaluation of breeding materials.
According to V.V. Ognev., N.V. Geraskina in recent years, the demand for fruits of alternative (alternative) colors -green, white and spotted -has become popular.Green fruiting forms are more common in China.300 samples of varieties from different ecological and geographical zones were studied in open and protected, provocative backgrounds.
As a result, a bank of 75 original and donor lines with valuable characteristics for various areas of selection in the conditions of the south of Russia, a collection of germplasm, was created.
The source material includes lines with high productivity and combinative ability, resistant to diseases and abiotic environmental factors, plants with different habitus, different colors and shapes, as well as lines with other characteristic fruits [1].
G. E. Russell emphasizes that the natural environment can be used as a background in the selection of resistance of agricultural crops to soil pests, in particular to the relief nematode [2].
M.H.Aramov notes that special research, as well as the results of thirteen years of scientific research, show that in the conditions of southern Uzbekistan, the natural invasion environment allows for an objective assessment of tomato varieties and hybrids in terms of resistance to the nematode [3].
Based on this, since 1997, SPE and KITI Surkhondarya scientific experimental station have been carrying out research on the selection of eggplant with early-early, valuable economic characteristics and resistance to the nematode.The uniqueness of the research is that the evaluation of breeding materials and the selection of resistant genotypes were carried out in a natural invasion environment.
The aim of the study is to create a starting source for the production of high-yielding, early-maturing, resistant to the blight nematode, varieties and F1 hybrids of eggplant with valuable economic traits.

Materials and methods
261 lines of eggplant belonging to the selection of the Surkhandarya Scientific Experiment Station and the Aurora variety included in the State Register served as the object of research.
Methods of research "Methodological guidelines for the study and maintenance of the world collection of the Nightshade culture (tomato, perets, eggplant) (1977), [4].Methodological guidelines for the selection of varieties and hybrids of pepper and valve for open and sheltered soil (1997).Experience is non-refundable.The plot area is 6.3 m 2 , the number of plants is 30, the plot is three rows.Planting scheme 70 x 30 cm [5].

Results and discussion
Since 2005, in order to create varieties and lines of eggplant with early, valuable economic traits, resistant to the tuber nematode, 3 promising second-generation hybrids were selected from the first-generation hybrids studied in 2001-2004: F2 Batayskiy x Almaz, F2 Matrosik x Almaz and F2 Matrosik x Solyaris hybrids in the breeding nursery was studied.
The experiment was studied by planting 200 plants from each hybrid.The studied eggplant lines belong to the early ripening group.F2Matrosik x Almaz and F2 Matrosik x Solyaris hybrids with the variety Matrosik resistant to the root-knot nematode are also resistant to the tuber nematode.
It is important to study the duration of the phases during the period of validity of the lines in the early selection of eggplant.
According to M.I.Mamedov.many authors, Erina (1958), Alpatev (1967), T.L. Loskutova (2006) who have studied the characteristics of the plant vegetation period and its importance for selection, emphasize the importance of knowing not only the general vegetation period, but also its separate phases.Forms with a tendency to intensive development and relatively early onset of phases at all stages of ontogeny are precocious.The duration of the vegetation period, that is, the time required for the plant to complete its development cycle, seed formation, and adaptation to the local conditions or technology [6,7,8,9].
In 2006-2008, a total of 88 high-generation lines isolated from the second-generation hybrids in 2005 on the basis of individual selection were planted in the eggplant breeding nursery.
15 of F3L-Bt/03 x L-Al/03 hybrid and 10 of F3 L-Mk/03 x L-Ss/03 hybrid and 14 of F3 L-Mk/03 x L-Al/03 hybrids in the 2006 eggplant selection nursery ta line was planted and studied.The duration of the development phases of the most promising of the studied lines was determined.Among them: Batayskiy x Almaz L-26, L-27 lines were early, in which the period of operation (from the germination of the seeds to the initial technical ripening) lasted 106 days.It was noted that the period from the day of germination of seeds to the first flowering was 96 days, and the period from the flowering of plants to the initial technical ripening of fruits was 10 days.
These plants are semi-branched, very tall (85-90 cm), and the fruit is oval in shape.Fruit weight (170 g) is small.The exterior of the fruit is smooth and shiny, dark purple, and the pulp is green in color.
The following: L-31, L-33, L-35, L-37, L-38, L-39, L-41, L-43, L-47 lines are early according to the validity period, which is 106-113 days continued.It was noted that the period from the day of germination of seeds to the first flowering was 99-100 days, and the period from the flowering of plants to the first ripening of fruits was 8-13 days.The height of plants (70-80 cm) was very high, strongly leafy, branched in L-35, L-39 lines, upright growing in L-43 line, semi-branched type in other lines.
The fruit is oval in shape.The appearance of the fruit in lines L-33, L-35, L-39 is dark purple, smooth shiny, and in lines L-31, L-37, L-38, L-41, L-43 and L-47 it is purple smooth shiny.
The pulp of the fruit is green in color, its weight is small (150-180g).Matrosik x Solyaris lines of the third generation were precocious and the period of validity lasted 108-110 days.It was observed that the period from the day of germination of seeds to the first flowering lasted 96-97 days, and the period from the flowering of plants to the first ripening of fruits lasted 11-13 days.In the L-50, L-55 lines, the plants are branched and very tall (75-80 cm).The fruit is oval in shape, pale purple in appearance, the pulp is yellow in color and close to the mother's shape.The fruit was small and weighed 160-170 g.
At the end of the application period, the roots of the plants were dug up and damage by the nematode was assessed.As a result, in the lines obtained from the Bataysky x Almaz combination, the average damage was 2.3 points, the development of the disease was 38.5%, the spread of the disease was 90.0%, and the resistance index was 61.5%.In Matrosik x Almaz combination lines, it was observed that the average damage was 0.8 points, the development of the disease was 11.5%, the spread of the disease was 23.0%, and the resistance index was 88.5%.In Matrosik x Solyaris combination lines, average damage was 0.92 points, disease development was 20.5%, disease spread was 35.0%, resistance index was 79.5%.In the process of evaluation, the seeds of the fourth generation lines were prepared by individual selection from high-yielding plants resistant to the crown nematode and studied in the eggplant breeding nursery in 2007.
In 2007, 19 fourth-generation lines were studied in the nursery.When the fruits are technically ripened, early, fertile, dark purple, smooth, shiny plants were selected and marked with special sticks.When the fruits on the plants were biologically ripe, their roots were dug up and their resistance to the nematode was evaluated (Table 1).
Single and group of resistant plants in this process by selection, resistant, fertile, earlymaturing plants were selected.
Bataysky x Almaz L-26-1, L-26-2, L-27-1, L-27-2 lines have an average damage of 1.3-2.1 points, and the development of the disease is 32.5-50.0%, the spread of the disease is 50-100%, and these lines are resistant to the nematode.In the comparative variety, the plants were severely damaged and it reached 3.0 points, the development of the disease was 75.0%, and the spread of the disease was 100%.
A number of new lines were isolated from the lines resistant to the tuber nematode by single and group selection.
The shape of the fruit was oval in lines L-34-1, L-35-1, L-39-1 and L-41-1, and cylindrical in all others.The appearance of fruits was dark purple smooth shiny in L-33-1, L-34-1 (Matrosik X Almaz) lines, purple smooth shiny in all other lines.It was found that the period from the flowering of the plants to the initial technical ripening of the fruits lasted 12-13 days, and they are considered very early.
From the studied lines, 13 fifth-generation lines were distinguished as the most promising (Table 2).
As can be seen from the table, only in line L-31-2 the plant type was branched and it was observed that it was different from the parent forms, while in lines L-48-1 and L-48-2 the plants grew erect, and in all other lines the plants became semi-branched.The plants are tall in lines L-31-1, L-31-2, L-35-1, L-47-1, L-47-2, L-48-2 (65-70 cm), in other lines (75-85cm) was too high As a result of individual selection carried out in 2008, cylindrical lines with the shape of the fruit were isolated and 6: L-34-1, L-35-1, L-35-2, L-35-3, L-38-1 and L-Lines 39-1 belonged.
The fruit weight in the lines at technical ripening was 160-200 g, which was 30-90 g less compared to the comparative variety.The productivity of the lines reached 5.0 points.
At the end of the application period, at the same time as the selection process, the roots of the plants were dug up and no infected plants were observed.
In 2008, as a result of the research, 35 individual selections were made from lines with resistance to nematode, precocity, valuable economic characters.
In 2009, 27 sixth generation lines were planted and studied in the nursery.The experiment was conducted in an environment heavily infested with nematode.According to the results of phenological observations, the duration of the development phases of the lines in 2009 was close to that of 2006, the period from the day of seed germination to the first flowering of plants lasted 92-95 days, and the period from the first flowering to the first technical ripening of fruits lasted 8-11 days.Their period of action is 101-104 days, and it is early.
In the process of selection, special attention was paid to the productivity of the plants, and the productivity (4.5-5.0 points) was high in all lines.
Depending on whether the studied lines are damaged by the nematode:  Explanation: cylindrical -cylindr In the process of studying high-generation lines in the breeding garden of eggplant, research work was carried out based on the requirements of the population of our country for the economic characteristics of this crop.
In the 2010 eggplant selection nursery, there were no significant changes compared to 2009 in terms of plant height and fruit color in the seventh generation lines.
It was observed that the shape of the fruit was cylindrical in L-31-1, L-38-3 lines, and oval in other lines.
In the process of evaluation of new lines of eggplant for resistance to the tuber nematode, resistance in 2010 compared to 2009 differed with a higher number of lines.In 2009, there were 3 lines, and in 2010, their number increased to 14.
In 2010, on the basis of individual selection from the seventh generation lines in the breeding nursery (F7), for use in the selection of high-yielding varieties with important economic characteristics and resistant to the nematode Matrosik x Almaz L-31-1, L-32-1, L-32-3, L-32-3/1, L-34-1, L-38-1, L-38-2 and Matrosik x Solyaris Lines L-47-1 were separated.In 2010-2011, compared to 2006-2008, the uniformity of the plants in the lines of the breeding nursery in terms of the shape, color, and weight of the fruits was quite different, in 2010 it was 90-95%, and in 2010-2011 it was close to each other.However, a slight difference was observed in their validity period, and in 2011, it was found that the validity period of the lines was extended by 9-12 days compared to 2010.We explained this due to the unfavorable weather conditions in the early spring of 2011, that is, the seedlings stayed longer in the greenhouse due to prolonged rainfall.
The high-generation lines studied in 2011 were divided into the and the earliest according to the period of validity.
The validity period for the earliest ones is the shortest (100-102 days); Lines L-32-1, L-32-2, L-31-1, L-31-2, L-32-3, L-37-1, L-38-1 and L-38-2 were introduced and they ripened 10-13 days earlier than the comparative variety.In the lines of this group, the plants were semi-branched.The height of the plants became high (60-75 cm).The shape of the fruit was long cylindrical in L-38-1 and L-38-2 lines, and cylindrical in the rest of the lines.The appearance of the fruit is dark purple in all perspective lines, the skin is smooth and shiny.This ensures their affordability.The fruit weight was small (150-200 g) in the lines and was found to be 40-90 g less than the comparative variety.In early lines, the period of action was 105-106 days and ripened 7-8 days earlier than the comparative variety.These include: L-32-4, L-39-1, L-39-2, L-47-1, L-47-2, L-47-3, L-47-4, L-48-1, Lines L-48-2 and L-48-3 belonged.In this group, the plant type was semibranched, and the height was very high (70-80 cm) and 10-20 cm lower than the comparative variety.
In the morning group; In lines L-47-3, L-48-3, L-48-1, and L-48-4, the fruit shape was elongated and cylindrical.Only in line L-32-3 the shape of the fruit became round.Productivity indicators were high in both groups of lines and it reached 4.5-5.0points.
In this environment, the average damage in the comparative variety was 3.5 points, the development and spread of the disease reached 100%, and it is unbearable.
Thus, in 2011, 55 individual selections were made on the best lines in the breeding nursery.As a result, early morning, to the signs of the economy resistant to serhocil and nematode: L-32-3, L-38-1, L-38-2, L-39-1 and L-48-1 and L-48-3 lines were isolated.
In 2012, 45 high-generation lines were studied in the breeding nursery, and 37 selections were made as a result of the research.In the early morning lines studied this year, the period of validity lasted 108-110 days.It was noted that the period from germination to the initial flowering of plants lasted 95-100 days, and the period from the initial flowering to the initial ripening of plants lasted 9-12 days.Act on the lines that the period was extended by 6-7 days compared to 2009-2010, in 2012 it is explained by a slight delay in the period from germination to initial flowering of plants.
Depending on the plant form, type, branching of Ertapishar lines:  the plant belonged to the upright growing lines: L-38-2, L-48-1, L-48-2, L-48-7 and L-48-8, in which the plant type was similar to the comparative variety (Table 4).It was observed that the plants were tall (65cm) in the L-48-7 line, and very tall (70-80cm) in the L-38-2, L-48-1, L-48-3 and 48-8 lines.Fruit shape is oval in line L-48-2, L-38-2, L-48-1, L-48-7 and L-48-8 and its lines became cylindrical, long cylindrical.It was noted that the fruit weight was small in these lines (150-180 g);  plant form branches: L-38-4 and L-48-5 lines are introduced, in which the plant is branched from below.In the lines belonging to this group, the ripening period was 107-108 days and ripened 6-8 days earlier than the comparative variety.In these, the plants became tall (60-70 cm).The shape of the fruit is long cylindrical in lines;  to lines with semi-branched plant form: L-38-1, L-38-3, L-32-3, L-39-3, L-47-1, L-47-2, L-47-3, L-47-4, L-47-5, L-47-6, L-48-3, L-48-4, L-48-6 and L-48-9 lines belonged.In these lines, the height of the plants was 75-80 cm, and they are considered very tall.The shape of the fruit is in this group: L-38-1, L-38-3, L-39-3, L-47-4, L-47-5, L-47-6, L-48-4, L-48 -6, L-48-9 lines were cylindrical, long cylindrical or similar to the fruit of the comparative variety, L-32-3 line was round and L-47-1, L-48-3 lines were oval.The weight of the fruit in the lines of this group was 120-200 g, which was 130-150 g less than the fruit weight of the comparative variety, and they are considered small-fruited.In the last 2-3 years, there has been a slight demand for round shaped eggplants in farmers' markets.Based on this, in the process of selection, attention was also paid to eggplant lines with round fruits, and the L-32-3 line was isolated, which will serve as a source for the creation of such varieties in the future.
In all of the promising lines analyzed above, the appearance of the fruit is dark purple, the skin is smooth and shiny.
Its productivity is 4.5-5.0 points and it is fertile.At the end of the period of operation, the root system of all lines was dug up and damage by the nematode was assessed.
Below is their description:  L-38-3/12.Morning.Plants are semi-branched, 80 cm tall.The shape of the fruit is long cylindrical, the appearance is dark purple, smooth and shiny.The weight of the fruit is 180 g, the fruit band is thornless.Productivity 5 points, prolific.Validity period is 110 days.Resistant to tuber nematode. L-48-1/12.Morning.Validity period is 108 days.The plant type is erect, 75 cm tall.
The shape of the fruit is long cylindrical, the color is dark purple, smooth and shiny.The weight of the fruit is 170 g, the fruit band is thornless.Productivity 5 points.
Resistant to tuber nematode. MJ 48-8/12.Morning.Validity period is 108 days.The plant type is erect, 75 cm tall.The shape of the fruit is long cylindrical, the appearance is dark purple, smooth and shiny.Fruit weight 160 g.Productivity 4 points.Resistant to tuber nematode. SP 48-9/12.Morning.Validity period is 107 days.Plants are semi-branched, 75 cm tall.The shape of the fruit is long cylindrical, the appearance is dark purple, smooth and shiny.Fruit weight 180 g.Productivity is 4.5 points.Resistant to tuber nematode.In 2013, 31 high-generation lines were studied for early maturity and resistance to tuber nematode.Matrosik x Solyaris L-47-6/1, L-47-6/3, L-47-7, L-47-1, L -47-9/1, L-47-9/2 lines were separated.These ripened 16 days earlier than the comparative variety.Eggplant line L-32-1 In all these lines, the plants became semi-branched, the outer appearance of the fruit was dark purple, and the skin was smooth and shiny.Below: L-32-1 (Figure 1), L-38-3, L-38-4, L-38-5, L-32-3 (Figure 2), L-47-6, L-In the lines 47-9, L-48-3 and L-47-1, L-47-1/1, the validity period was 104-108 days and the comparative variety was 9-13 days shorter than the validity period.These lines are also early [2,3]  In recent years, the fruit shape and appearance of the eggplant has been given a lot of attention at farmers' markets.Based on this, in the process of research and selection, special attention was paid to the shape and appearance of the fruit of the plants.Taking this into account, we will use as material for the creation of varieties and lines of eggplants with different fruit shapes in the future selection work:  the shape of the fruit is cylindrical (the length of the fruit is 13-16 cm): lines L-32-1, L-47-9/1 and L-48-3; The shape of the fruit is long cylindrical (fruit length 17-22 cm) for the selection of varieties and lines L-38-4, L-38-5, L-47-1, L-47-1/1, L-47-1/2, L-47-1/3, L-47-6/1, L-47-6/ 2, L-47-6/3, L-47-7/1, L-47-7/2, L-47-9/1, L-47-9/2, and L-47-9/3 lines;  the shape of the fruit is round and oval, and for the selection of lines L-32-3 and L-31-5 lines were selected.Fruits (135-250 g) in early lines were small and medium in weight.Productivity was 4.5-5.0 points in all lines and they are considered fertile.At the end of the application period, when the roots of the lines were dug up and the damage by the nematode was assessed, 100% of the plants were resistant to the nematode in the lines L-38-2/3, L-38-3/1, L-47-2/1 and L-47-7/2 showed and these lines were isolated for use as material in resistance selection.
The round L-32-3 line of eggplant, identified as promising as a result of research, was submitted to the State Variety Testing Commission from 2021 under the name of the Globus variety.
Early Globus (L-32-3) variety created as a result of research was submitted to the State Variety Testing Commission from 2021.
The early varieties and lines isolated as a result of the research will serve as valuable starting material for the future creation of varieties and hybrids resistant to the early spring nematode.
Globus variety and new lines of eggplant are recommended for growing in vegetable farms heavily affected by the nematode.
-Development of the disease, R -Spread of the disease, IU, % -durability index.

Table 1 .
Eggplant (F4) with the nematode of the fourth generation lines damage level (2007).

Table 3 .
Damage of early(F8) high generation lines of eggplant by the nematode, (2011).

Table 4 .
Economic and morphological characterization of the ninth generation lines resistant to tuber nematode (F9) (2012).