Abstract: This study was carried out to determine mutation effects and to investigate the positive mutant types that can be emerged as a result of this mutagen effect at Acalpi 952 cotton cultivar. Gamma irradiation was employed at 100, 200, 300 and 400 grey doses at Turkish Atomic Energy Foundation. Irradiated seeds from each dose were sown separately to form M1 generation (first mutation generation) and the surviving seeds were collected afterwards. In M2 generation (second mutation generation), seeds form each plant were grown as one a pice row and some characteristics were studied and 36 lines were selected according to yield and yield components. In M3 generation, 36 lines that selected M2 generation with three standard cultivars were made yield and adaptation experiments according to Complete Block Design with three replications. At the and of studies for three years among 2000-2002 growing period, ACH8, ACH9 and ACH25 lines were find as superior lines according to yield and yield components. On the other hand these lines were obtained high yielded from standard cultivars.
INTRODUCTION
Cotton is an agricultural and industrial crop. Therefore farmers prefer cotton cultivars that are early maturing, high yielding and resistant biotic and abiotic stress conditions, although textile industry prefer cotton seed yield with high lint percentage, more fineness and strong fibers. The cultivars with superior fiber technological characters are bought in high prices. In order to develop new superior cotton cultivars, one method is mutation breeding. Mutations are known to enhance the genetic variability of crop plants as the variability at species level has reached the ceiling due to high breeding intensity and rapid erosion of genetic resources. Since spontaneous mutations occur at very low frequency, induced mutations facilitate the development of improved varieties at a swifter rate. Cotton is an economically important crop plant and cultivated in many parts of the world and it is a leading fiber crop, the second best potential source of plant proteins and fifth best oil-producing crop. In addition to being the world's most important textile fiber crop, cotton is also an important source of edible oil and protein. Among the different breeding methods used, mutation induction has been used as an important tool to supplement existing variability and to create additional variability for qualitatively as well as quantitatively inherited traits in cotton, especially various degrees of resistance to biotic and abiotic stress, number of bolls, seed yield and oil content (Muthusamy et al., 2005). The conventional breeding methods are usually very labourous take long time and are expensive. For that reasons, mutation breeding has been used in the last years, because this method takes less time and new superior cultivars could be developed easily (Baysal et al., 1994, Yiidirim and Tugay, 1977). There are different type of chemical and radiation mutagens. Gaul (1977) and Mukhov (1987) reported that the achievement in mutation breeding, related to living species, mutagens, dose of mutagens applications and application methods]. In addition, cotton seed radiated with cobalt 60, superior mutant lines were found according to parent cultivars in view of morphological characters and the most suitable radiation dose were determined at 100 and 200 Gray (Constantin, 1968; Karaevoi et al., 1981; Atilaa and Peokircioglu, 1990; Vlkova, 1992). Meanwhile it is reported that seeds dead with application high radiation and its obtained that low mutation frequency, by reason demand of physiological in M1 generation (Gençer et al., 1992; Baysal at al., 1994). On the other hand the high mutagen dose applications affect negative mutation (Tagiev, 1984). Some researchers have reported that mutagen applications are increased, but higher doses decreased the plant height (Yiidirim and Tugay, 1977) at wheat and barley (Karaevoi et al., 1981; Tyaminov, 1982; Kuodemir,, 1999) at cotton (Özbek et al., 1986; Saeel, 1994) at soybean (Hatipoglu, 1999) at vetch. The mutagens affected number of sympodial and monopodial branches and caused of some lines high or low value of cotton (Gaul, 1977; Kuodemir, 1999). In another study, mutagen applications affected boll weight and boll number per plant (Ibragimov et al., 1989; Kuodemir, 1999). According to Mamedov and Bazhanova (1987), higher radiation applications had negative effects on fiber yield, fiber length and boll weight of many plants. On the other hand, selected from M2 and M3 generation some lines have been using cotton improvement. Some researchers Kerbabeva et al. (1984), Ibragimov et al. (1989), Kuodemir, 1999) reported that mutagen applications increased the number of boll, boll weight and 100 seed weight. Kurepin et al. (1985) announced that, mutagen applications affected 100 seed weight. Meanwhile, according to Kuodemir (1999), mutagen applications were ineffective on 100 seed weight in cotton.
Cotton fiber is a unique raw material for the textile industry. Increase in world population and, rise of living standard, textile products have to be increased. For that reasons, textile industry prefers quality cotton in terms of fiber length, high lint percentage, fiber strength, fiber fineness, fiber uniformity etc. Therefore, breeders have to improve these characters. Mutagen applications create variation on genetic structure. Some researchers had reported that, mutagen applications had caused variations on fiber characters and by selecting the superior progenies, the new superior cultivars can be developed (Kuliev, 1983; Kerbabeva et al., 1984; Tagiev, 1984; Ibragimov et al., 1989; Mamedov and Bazhanova, 1987; Gençer et al., 1992; Auld et al., 1998; Raffat, 1998; Kuodemir, 1999). On the other hand, mutagen applications that had made artificial mutation, caused to earliness, 100 seed weight, cold and dry tolerance and verticillium and the genetic structure has been changed and could be improved were reported (Aitzhanov, 1984; Bughio et al., 1984; Mamedov and Bazhanova, 1987; Kuodemir, 1999).
The objective of this study was to investigate to develop new cotton cultivars through mutagen (cobalt 60) applications.
MATERIALS AND METHODS
Materials: The experimental materials used in this study consisted of Acalpi-1952 (Gossypium barbadense L.) cultivar. Acalpi-1952 cv is taken from Cagdas Seed Agency that placed in Turkey representation by Hazera Seed Company in Israel. This Cultivar has thin, long and strong fibers and resistant to dry, but it has long vegetation period.
The experiment field was sandy clay, pH 7.4-7.6, amount of lime 24.45, available phosphate and potassium 3.1 and 69.1 kg day-1, organic matter content 2.01% (Anonymous, 2003) At the region, 400 mm total rainfall, from 30.8 to 46.5EC maximum, from -6 to 16EC minimum, from 12.9 to 31.5EC average weather hot were fixed from may to November in 2002. The proportional moisture was fixed from 27 to 58% (Anonymous, 2003).
Methods
The first year studies (M1 generation): Original seeds
of Acalpi-1952 cv (Gossypium barbadense L.) was ensured from Cagdash
Seed Agency that placed in Turkey representation of Hazera Seed Company in Israel.
The seeds of Acalpi-1952 cultivar had counted 4H1000 and then put nylon baggies separately. The baggies that content seeds were irradiated 100, 200, 300 and 400 gray doses with cobalt 60 mutagen in Atom Energy Foundation of Turkey, at 17.04.2000. The seeds belong every irradiated doses (100, 200, 300 and 400 gray) were sown at separately plots in Harran University Agricultural Faculty experiment fields at 19.04.2000. Each plots consist have 25 rows with ten meters length was established at a 80 centimeters row spacing and plants were placed 25 cm apart on beds. The edge rows of every plot were sown control cv. (no radiation). Necessary cultivation process (irrigation, cultivation and fertilization) were apply to experiment.
During this study, the following parameters were recorded.
| Date of emergence | |
| Plants were count on the rows for twice (15 and 30 days after planting). | |
| Date of flowering. | |
| Each plants (about 1, 000) were evaluated in terms of agricultural characters. | |
| Seed and lint index | |
| Boll number | |
| Number of sympodial branch | |
| Boll weight | |
| Earliness | |
| Weight of hundred seeds | |
| Number of carpel | |
| Fiber quality |
On the other hands every radiation doses content plants were self pollinated especially at first three week of flowering.
The plants of every plot had been made self pollinated by hand and then determined of as superior plants were be harvested separately and put bagged. The boll number and boll weight of every single plant had evaluated. The following characters were been investigated.
The second year studies (M2 generation): The seeds that obtained from single selected plants at M1 generation had been sown by hand at 25.04.2001. The experiment design was Randomized Complete Block design with three replications. In this study, every experiment plot consist of two plant rows, because of not enough seeds belong selected single plants. The seeds were sown 5 m length rows was established at a 70 cm row spacing and plants were placed 25 cm apart on beds. Essential cultural processes were been applied to experiment. The following characters were determined in M2 population according methods of Senel (1980) and Gençer et al. (1992).
| Plant height, | |
| Number of sympodia per plant | |
| Boll weight | |
| Number of boll per plant | |
| Number of Fruit per plant | |
| Seed cotton of boll weight (g) | |
| Seed cotton yield per plant (g) | |
| Seed cotton yield per day (kg) | |
| Earliness | |
| Weight of hundred seeds (g) |
The superior 36 line belong Acalpi-1952 cv. (Gossypium barbadense L.) were selected from M2 population.
The third year studies (M3 generation): The selected from M2 generation 36 lines with standard and control cultivars (Sayar 314 and Stoneville-453 and control Acalpi-1952) were sown by hand of 70H20 cm plant density in Harran University Agricultural Faculty experiment fields at 23 April 2002. Each plots of experiment have consists of 4 rows with 10 m length. The experiment was established according to randomized complete block design with three replications. The necessary cultural process were applied. First and second harvesting of the experiment=s were been done at 1 October and 28 October 2002. The following characters were obtained from 20 plants selected by change in each plots,
| Plant height, | |
| Number of sympodial branches | |
| Number of boll per plant | |
| Boll weight | |
| Seed cotton yield per plant (g) | |
| Number of sympodial per plant | |
| In addition, the following characters were found from each plots | |
| Seed cotton yield per day (kg) | |
| Earliness | |
| Seed and lint index | |
| 100 seed weight | |
| Fiber quality |
TARIST statistical analysis packet program was used in the statistical analysis (Ackgoz et al., 1993) and Duncan method had been used to classification significant differences between lines and standard cultivars.
RESULTS AND DISCUSSION
The results of some yield and yield components of mutant lines from obtained M3 population and standard cultivars are shown in Table 1 and 2, some fiber technological characters are given in Table 3.
Plant height: As noticed in Table 1, the highest plant height was obtained from ACH3 line height belong cultivars and lines were changed from 70.70 to 111.13 cm. at 100 Gray dose, while the lowest plant height was from ACH23 line at 300 gray radiation dose. Compared to the control Acalpi, some of the lines (ACH3, ACH31, ACH1, ACH2) had found higher from control cultivars on plant height. Meanwhile, extreme plant height was not observed among the lines compare to the controls. The similar results were obtained by Karaevoi et al. (1981), Tyaminov (1982) and Kuodemir (1999).
Number of sympodial branches: Number of sympodial branches have been affected on number of flower and number of boll, therefore it is an important character for cotton cultivation. As shown in Table 1, number of sympodia branches of cultivars and lines were changed from 14.83 to 23.67 per plant. The highest number of sympodia per plant were obtained from ACH31, ACH3 and ACH12 lines while the lowest was found from Acalpi cultivar. All radiation doses have affected positive and negative on number of sympodial branches. Compared to the control Acalpi, all lines were found higher from it. Similar results were obtained by some investigators (Gaul, 1977; Kuodemir, 1999).
Number of boll per plant: Boll number is an important for cotton seed yield. For that reason it has wishes high. The effect of cobalt 60 mutagen was indicated positive and negative of lines on boll number per plant (Table 1). Boll number per plant of cultivars and lines were indicated from 11.73 to 24.60. The highest boll number per plant was found from ACH8 line while the lowest was found from ACH6 line. These two lines belong 100 gray radiation dose application. The radiation applications were created variation on boll number per plant. Boll number of some lines (ACH8, ACH9, ACH22, ACH25, ACH30, ACH36) were indicated higher from control Acalpi and some (ACH8, ACH25, ACH25) were passed control Sayar 314 cv that can the highest boll number per plant among control cv.
| Table 1: | Results for plant height (cm), number of sympodial branches,
number of boll per plant, number of fruit per plant and boll weight at different
cobalt 60 aplication doses |
| Values followed by different letter(s) differ significently at p<0.05 | |
The result in this study confirms the similar results obtained by Kerbabeva et al. (1984), Ibragimov et al. (1989) and Kuodemir (1999).
Number of fruit per plant: The effects of radiation applications were caused genetic variations on number fruits per plant (Table 1). On the other hands, number of fruit per plant is related to earliness. For that reason, more fruit number per plant is not desirable. Fruit number of cultivars and lines were changed from 6.95 to 3.89 per plant. The lowest number of fruit per plant were indicated ACH2 and ACH5 while the highest were indicated ACH36 line. Most of lines have been got lower fruit number from control Acalpi and the other standard cultivars. The similar results were found by Kuodemir (1999).
Boll weight (g): As shown in Table 1, the effects of radiation applications on cotton seeds were obtained positive and negative on boll weight. Boll weight of cultivars and lines were changed 3.89 to 6.95 g. The highest boll weight was obtained from ACH36 line while the lowest was obtained from ACH2 line. Boll weight of lines, compared with control Acalpi and the other standard cultivars, it can said that, radiation applications were created genetic variation on boll weight. Meanwhile boll weight of some lines (ACH4, ACH8, ACH9, ACH12, ACH17, ACH21, ACH22, ACH25, ACH31, ACH36) were increased, the others had been decreased. The result in this study confirms by Kerbabeva et al. (1984), Ibragimov et al. (1989) and Kuodemir (1999).
Seed cotton boll weight: Seed cotton boll weight is an important character of yield per unit area. For that reasons it should be high. Seed cotton boll weight of cultivars and lines belong experiment were changed from 2.33 to 5.22 g (Table 2).
| Table 2: | Results for seed cotton boll weight (g), seed cotton yield
per plant (g), seed cotton yield per da (kg), earliness ratio (%) and hundred
seed weight (g) at different cobalt 60 aplication doses |
| Values followed by different letter(s) differ significently at p<0.05 | |
The highest seed cotton boll weight were obtained from ACH36 lines that created from 400 gray radiation applications. Seed cotton boll weight were affected from cobalt 60 applies and it can say that 200 and 300 Gray doses of cobalt 60 applies were decreased seed cotton boll weight. Meanwhile ACH25 and ACH36 lines were placed among high values. However, some lines (4, 10, 17, 22, 25, 26, 31, 36) were found high from control Acalpi. The result in this study confirms the similar results found by Kerbabeva et al. (1984), Ibragimov et al. (1989) and Kuodemir (1999).
Seed cotton yield per plant (g): Yield per plant plays important role on yield per unit area. For these reasons yield per plant wishes higher. According to our results, it can said that the affects of radiation applications were caused genetic variations on yield per plant (Table 2). Yield per plant of cultivars and lines were changed from 28.26 to 97.32 g. The highest seed cotton yield per plant were obtained from ACH36 and ACH22 lines, while the lowest was obtained from ACH5 line. As a matter of fact, sympodia number per plant, number of fruit, seed cotton boll weight of ACH36 and ACH22 lines were obtained higher from the other lines (Table 1). Seed cotton yield per plant of lines, when compared with control Acalpi and the other standard cultivars, it can said that radiation applications were created genetic variation on seed cotton yield per plant. In addition, ACH8, ACH9, ACH10, ACH17, ACH22, ACH25 and ACH36 lines were placed in high values. These lines were created from 100, 200, 300 and 400 Gray radiation doses applies. The similar results were obtained by Kerbabeva et al. (1984), Ibragimov et al. (1989) and Kuodemir (1999).
Seed cotton yield (kg ha-1): According present results the effects of radiation applies were caused genetic variations on total seed cotton yield (Table 2).
| Table 3: | Results for ginning outturn ratio (%), fiber thickness (mic),
fiber stronght (g/tex), fiber height (mm), uniformity (%) at different cobalt
60 aplication doses |
| Values followed by different letter(s) differ significently at p<0.05 | |
Total seed cotton yield of cultivars and lines were changed from 1820 to 4902 kg ha-1. The highest total seed cotton yield were indicated ACH22 and ACH36 lines, while the lowest were indicated ACH6 line. On the other hands while control Acalpi-1952 was given 2439 kg ha-1, Sayar 314 and Stoneville-453 standard cultivars of study were given 3421 and 3928 kg ha-1, respectively. Some lines (ACH8, ACH9, ACH22, ACH25, ACH36) were higher from the super standard cv. in terms of total seed cotton yield. As a matter of fact, sympodia number per plant, number of fruit, seed cotton boll weight of these lines were found higher from the other lines. Similar results were obtained by Kerbabeva et al. (1984), Ibragimov et al. (1989) and Kuodemir (1999).
Earliness (%): First harvesting ratio is an important scala for earliness, there for it have been desired high. As noticed Table 2, the affects of radiation applications on first harvesting ratio were obtained positive and negative. First harvesting ratio of cultivars and lines were changed 68.9 to 93%. The highest first harvesting ratio was obtained from ACH1 line, while the lowest was obtained from ACH2 line. First harvesting ratio of lines, when compared with control Acalpi and the other standard cultivars, it can said that radiation applications were created genetic variation on first harvesting ratio. Some lines (1, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 18, 19, 20, 21, 22, 23, 25, 26, 27, 30, 31, 32, 34, 35 36) were found higher from control Acalpi and the other standard cultivars. It can say that these lines earlier from the other lines and cultivars of experiment. The similar results were reported by Aitzhanov (1984), Bughio et al. (1984), Mamedov and Bazhanova (1987) and Kuodemir (1999).
Hundred seeds weight (g): As shown in Table 1, the effects of radiation applications on hundred seeds weight had been positive and negative. Hundred seeds weight of cultivars and lines were changed 8.85 to 12.48 g. While the highest hundred seeds weight was obtained from ACH29 line that applied 400 Gray radiation applies, the lowest was obtained from ACH34 line. Hundred seeds weight, when compared with control Acalpi and the other standard cultivars, it can said that radiation applications were created genetic variation. The result in this study confirms the similar results obtained by Aitzhanov (1984), Bughio et al. (1984), Kerbabeva et al. (1984) Kurepin et al. (1985), Ibragimov et al. (1989) and Mamedov and Bazhanova (1987). On the other hands some researcher was reported that, mutagen applications were not affected on hundred weight in cotton (Kuodemir, 1999). This situation might be different genotypic structure, different ecological conditions, different mutagen and its dose applications.
Fiber technological characters: Fiber technological characters are very important in textile industry. In this study was investigated follow characters.
Lint percent: As noticed in Table 3, lint percent of cultivars and lines belong experiment were changed from 27.8 to 39.6%. The highest ginning outturn were indicated from ACH22 and ACH36 lines that applied 300 and 400 gray radiation doses, meanwhile these lines were found higher from control Acalpi and the other standard cultivars. On the other hand, radiation applies were created variation on lint percentage. Two lines (ACH22 and ACH36) were found higher from control Acalpi and the other standard cultivars, however the others were found lower from the point of view of lint percent. Similar results were obtained by some investigators (Kuodemir, 1999).
Fiber fineness: Fineness is play important role in textile industry and it is desired quiet thin. As shown in Table 1, the affects of radiation applications on fiber fineness were obtained positive and negative. Fiber fineness of lines and cultivars were changed from 4.57 to 2.97 mic index. The thinnest fibers were found from ACH1, ACH14, ACH30 and ACH34 lines, nevertheless the thickest fibers were found ACH24 line. On the other hand while control Acalpi was given the thinnest fiber from the other standard cultivars, in a lot of lines were obtained thinner fiber from control Acalpi. According to our M3 population results, it can said that radiation applications on cotton seed, were decreased fiber fineness. The similar results were reported by Kuliev (1983), Kerbabeva et al. (1984), Tagiev (1984), Ibragimov et al. (1989), Mamedov and Bazhanova (1987), Gençer et al. (1992), Auld et al. (1998), Raffat (1998) and Kuodemir (1999).
Fiber strength: Fiber strength is an important character in terms of textile industry. As shown in Table 1, the effects of radiation applications on fiber strength were obtained positive and negative. Fiber strength of cultivars and lines were changed from 24.47 to 36.33 g/tex. The highest fiber strength was obtained from ACH6 line while the lowest was from ACH22 line. According to Table data, The most strength fiber was found control Acalpi of control cultivars. In addition to this, some of lines (2, 3, 4, 5, 6, 8, 11, 12, 14, 15, 28, 29 and 30) were indicated higher values. The result in this study confirms the similar results obtained by Kuliev (1983), Kerbabeva at al. (1984), Tagiev (1984), Ibragimov et al. (1989), Mamedov and Bazhanova (1987), Gençer et al. (1992), Auld et al. (1998), Raffat (1998) and Kuodemir (1999).
Fiber length: Fiber length plays leading role in textile industry. Quality thread is made only from longer fibers. As noticed in Table 3, the affects of radiation applications on fiber length were obtained positive and negative but, this variation was not significant from statistical methods. Fiber length of lines and cultivars were changed from 28.23 to 33.90 mm. On the other hand while control Acalpi was given the most length fiber from the other standard cultivars, in a lot of lines were obtained more length fiber from control Acalpi. The most length fibers were obtained from ACH26 line that created from 300 Gray radiation applies, while the shortest was from ACH6 line. Some lines (ACH7, ACH9, ACH16, ACH20, ACH26, ACH28, ACH30) were given longer fiber from superior cultivar. The similar results were reported by Mamedov and Bazhanova (1987) and Kuodemir (1999).
Uniformity (%): As noticed in Table 3, fiber uniformity of cultivars and lines belong experiment were changed from 81.57 to 85.07%. The highest uniformity was indicated from ACH30 line that applied 400 Gy radiation dose, meanwhile these line were found higher from control Acalpi and the other standard cultivars. On the other hand the lowest fiber uniformity were found from ACH23 and ACH34 lines. According to our study, the radiation applies were not statistically significant on fiber uniformity. The result in this study confirms the similar results obtained by Kuodemir (1999).
CONCLUSIONS
Sayar-314 and Stonovil-453 (G. hirsutum L.) are standard cultivars of Sout East Anatolia in Turkey. These cultivars have medium length fibers and are not resistant to hot, dry and salty. Acalpi-952 (G. barbadense L.) cotton cultivar has quality fiber and resistant to dry. This study was conducted that to improve new superior cotton cv. from these cultivars. According to result of M3 generation, ACH8, ACH9, ACH17, ACH22, ACH25 and ACH36 lines were found good position in view of seed cotton yield per ha. These lines were found higher yielded from control Acalpi and standard cultivars (Stonovil-453 and Sayar-314) of region. In addition these lines had higher values in terms of some yield components (number of sympodia, number of boll, boll weight, seed cotton boll weight and yield per plant) (Table 1-3). Nevertheless, ACH8, ACH9 and ACH36 lines were indicated super characters from parent Acalpi and standard cv. in terms of yield and fiber technological characters. These lines were obtained hopeful. It is suggested that the studies must be continue to M6 generation.