New insights on inheritance of multilocular trait in yellow sarson Rare inheritance studies in yellow sarson for petalous and apetalous trait

doi:10.21203/rs.3.rs-3432880/v1

The inheritance study for the multilocular trait would open new doors for better yield in yellow sarson getting to know the genetic nature helps the breeder to work efficiently and transfer the trait due to its nature of having more seeds This study uses crosses between multilocule and bilocule parents Pant Girija, B9, are bilocular parents and pant pili sarson 1, NDYS are multilocular parents which were crossed and f1, f2, bc1, bc2 generations were studied and chi2 test was applied to get the nature of gene and inheritance. The findings reveal critical insights for the plant breeding industry. Multilocular genotypes are completely dominant in the F1 generation, demonstrating the usefulness of this feature for breeding. The regulation of locules by a single dominant gene is evident in the F2 generation, which displays a clear Mendelian 3:1 segregation ratio. Experiments with backcrosses support the dominance of multilocular alleles. These findings are highly applicable to plant breeders and will help them to precisely pick traits and improve desired traits in Brassica cultivars. Strategic breeding efforts can increase crop quality and production by better understanding the genetics of ovary locules.

multilocule

bilocule

brassica

breeding

- Yellow sarson (Brassica rapa var. Yellow sarson) is an important agricultural crop,, being one of the most significant oil crops, produces edible oil for human use, protein-rich feed for livestock, and raw materials for industrial processes. The primary purpose of rapeseed breeding was to increase yields(Xu etal., 2021). Previous research found that the number of siliques per plant, number of seeds per silique, and seed weight were the most important parameters influencing rapeseed yield (Katiyar et al., 1998; Lv et al., 2012; Zhao et al., 2003). It is critical to analyze the properties of the silique as the organ that develops seeds in order to improve yield (Liu, 1987). The major variables used to quantify yield per unit area in current rapeseed genetic improvement efforts are the number of effective siliques per unit area( Xu etal., 2021), the number of seeds per silique, and the weight of a thousand seeds. The major goals for developing new cultivars for high-density seeding are to increase the quantity of seeds per silique and seed weight ( Zhu et al., 2010). Now, the development of new rapeseed cultivars usually correlated to direct broadcasting, dense planting, and mechanization (Song et al., 2010). The quantity of siliques per plant and the number of seeds encapsulated within these siliques have been identified as significant determinants of yellow sarson yield. As a result, genetic improvement efforts in yellow sarson are motivated by the need to enhance the number of effective siliques per plant, as this directly contributes to production. Bilocular variants have lower yields than multilocular germplasm(Zhao et al., 2003). and yellow sarson cultivars, owing to the fact that they produce fewer seeds per pod. This lower seed production has a direct influence on crop yield. Multilocular germplasm of yellow sarson cultivars, on the other hand, often produce more seeds per pod, resulting in better crop output. Understanding the inheritance of these traits, particularly the multilocular and bilocular qualities, is critical in these cases.Consequently, by unraveling the genetic mechanisms governing these traits, we can make informed decisions to develop high-yielding yellow sarson varieties, thus ensuring a more prosperous and sustainable agricultural future. Since it is crucial for breeding high-yield Brassica crops, researchers have been thoroughly examining the inheritance of the multilocular trait for many years (Xu et al., 2021). As stated by (Zhao et al. in 2003), it was formerly thought that this feature in Brassica juncea was predominantly controlled by one gene and modified by a minor gene, with no participation of cytoplasmic factors. However, as the feature's importance has increased, more recent genetic investigations in rapeseed have shown that it is a qualitative trait controlled by one or two pairs of nuclear recessive genes. A single nuclear recessive gene governs this feature in the diploid species Brassica rapa (AA), according to a study by( Fan et al., 2014)Brassica juncea (AABB), an allotetraploid plant, is controlled by two separately inherited recessive nuclear genes, as shown by (Xiao et al. in 2013) research. The genetics of multilocularity has been discovered, and this holds enormous promise for the breeding of yellow sarson and the sustainability of agriculture. It emphasizes how crucial it is to carry out additional inheritance research on features like multilocularity and bilocularity that have a big impact on crop yields. Understanding the complex genetic pathways underlying these qualities will allow us to generate high-yielding yellow sarson cultivars, enabling a more affluent and resilient agricultural environment. The experiment has determined how multilocular trait inheritance works.

Yellow sarson plants with various ovary locule conditions used as the plant materials for this investigation. NDYS and Pant pili sarson1with multilocular ovaries, B9 with bilocular ovaries, and Pant girija with bilocular ovaries were chosen as the three parental lines to cross. The F1, F2, and backcross generations were produced using these parental lines as a base.the experiments were performed at GB Pant university of agriculture and technology Pantnagar

Crossing and Generation of Offspring: To investigate the inheritance of ovary locules in Brassica, crosses were made between the parental lines. The resulting offspring were organized into the following generations:2019 the materials were crossed for generation of f1 then 2020 fresh f1 and bc1 bc2 were generated and 2021 evaluation of generations were done for each cross

F1 Generation: In this generation, the offspring consisted of plants resulting from the initial crosses between NDYS (multilocule) and B9 (bilocule) and between Pant girija (bilocule) and Pant pili sarson1 (multilocule). A total of 30 plants from the NDYS x B9 cross and 40 plants from the Pant girija x Pant pili sarson1 cross were examined for ovary locule condition.

F2 Generation: The F1 plants were allowed to intercross, producing the F2 generation for each cross. A total of 266 plants from the NDYS x B9 cross and 300 plants from the Pant girija x Pant pili sarson1 cross were analyzed for ovary locule condition.

Backcross BC1P1 (F1 x NDYS): Backcrossing was performed between F1 plants and the NDYS parent, which had multilocular ovaries. A total of 360 plants were examined in the NDYS x B9 backcross, and 370 plants were examined in the Pant pili sarson1 x Pant girija backcross.

Backcross BC1P2 (F1 x B9): Another backcross was carried out between F1 plants and the B9 parent, which had bilocular ovaries. A total of 340 plants were analyzed in the NDYS x B9 backcross, and 360 plants were analyzed in the Pant girija x Pant pili sarson1 backcross.

Data Collection

For each generation and cross, the ovary locule condition of individual plants was recorded as either multilocular or bilocular. The observed frequencies of each ovary locule type were documented.

Chi-Square Analysis:

Chi-square (χ²) analysis is a statistical method used to evaluate the goodness of fit between observed data and expected data in categorical variables. In the context of this study on ovary locule inheritance in Brassica, chi-square analysis was employed to determine whether the observed ratios of multilocular to bilocular ovaries in different generations and crosses conformed to the expected Mendelian ratios.

The formula for calculating the chi-square value (χ²) is as follows:

χ² = Σ [(Observed frequency - Expected frequency)² / Expected frequency]

Observed frequency: The actual number of individuals exhibiting a specific trait (e.g., multilocular or bilocular ovaries).
Expected frequency: The number of individuals expected to exhibit a specific trait based on Mendelian inheritance ratios.

The chi-square value measures the extent to which the observed data deviate from the expected data. A higher chi-square value suggests a greater deviation from expected values, while a lower value indicates that the observed and expected data are in closer agreement.

To assess the significance of the deviation, the calculated χ² value is compared to a critical value from a chi-square distribution table at a predetermined level of significance (typically 0.05) and degrees of freedom. If the calculated χ² value is less than the critical value, it suggests that the observed data do not significantly deviate from the expected Mendelian ratios, indicating that a single dominant gene likely controls the trait under investigation.

Chi-square analysis is a valuable tool in genetics and statistical genetics to test hypotheses about the genetic basis of traits and the presence of Mendelian inheritance patterns.

Inheritance of multilocular trait cross between NDYS(Multilocular) X B9 (Bilocular)- The purpose of the study was to cross NDYS, which has a multilocular ovary, and B9, which has a bilocular ovary, in order to look at the inheritance of ovary locules in Brassica. Data was gathered while the Fl, F2, and backcross generations were being developed. All 20 plants in the Fl generation had multilocular ovaries, demonstrating the dominance of this feature.

Out of 250 F2 plants, ovary locules were found to be segregated, with 185 plants having multilocular ovaries and 65 having bilocular ovaries. With a chi-square value of 0.08, this segregation showed a 3:1 ratio (multilocules to bilocules), indicating that ovarian locules are regulated by a single dominant gene.

All 350 plants in the F1 backcross with the dominant parent (BC1P1, F1 x NDYS) had multilocular ovaries. On the other hand, when combining F1 with With a chi-square value of 0.08, this segregation showed a 3:1 ratio (multilocules to bilocules), indicating that multilocular genotypes are regulated by a single dominant gene. Fig.1 showed the frequency of genotypes in various generations leading to clear picture of inheritance pattern

On the other side, when we look at the offspring resulting from a cross between an F1 plant and a recessive parent, specifically BC1P2 (F1 x B9), we observed a total of 340 plants. Out of these, 175 of them displayed multilocular siliqua, while 165 had bilocular siliqua. The chi-square value calculated from this data was 0.28. This data strongly suggests that the presence of multilocular genotype is dominant over bilocular genotypes and is controlled by a single dominant gene.

The way these traits segregate in these generations indicates that the number of locules in the siliqua is determined by a single gene.

Table 1: Inheritance pattern of ovary locules in different generation of cross NDYS (multilocule) x B9 (bilocule)

Generation

Total no. of plants

Expected frequency

Observed frequency

Expected ratio

X²cal

X2

tab (0.05,

1 df)

Multilocule

Bilocule

Multilocule

Bilocule

F

1

20

0

20

0

F

2

250

187

63

185

65

3:1

0.08

3.84

BC P (F x

1 1 1

NDYS)

350

0

350

0

1:0

0.00

3.84

BC₁P₂ (F x

1

B9)

340

170

175

165

1:1

0.28

3.84

Table 2: Inheritance pattern of ovary locules in different generation of cross NDYS (multilocule) x Pant girija (bilocule)

Generation

Total no. of plants

Expected frequency

Observed frequency

Expected ratio

X²cal

X2

tab (0.05,

1 df)

Multilocule

Bilocule

Multilocule

Bilocule

F

1

30

0

20

0

F

2

266

199

67

190

76

3:1

1.6

3.84

BC P (F x

1 1 1

NDYS)

360

0

360

0

1:0

0.00

3.84

BC₁P₂ (F x

1

Pant girija)

340

170

175

165

1:1

0.28

3.84

Inheritance of multilocular Trait in different generation of cross NDYS (multilocule) x Pant girija (bilocule)

In order to investigate ovary locule inheritance in Brassica, we crossed the multilocule NDYS with the bilocule Pant Girija. This study has far-reaching consequences for plant breeding programs and crop enhancement. Table 2 shows that: • Generation F1: A surprising and consistent expression was seen in the initial F1 generation of 30 plants—each and every plant had multilocular ovaries. This consensus result strongly demonstrates the multilocular trait's supremacy over its bilocular cousin. In this generation, the observed ratio was a resounding 100% multilocule, indicating the presence of a single dominant gene.

The F2 generation, which included 266 plants, displayed a Mendelian segregational ratio, mimicking the genetic dynamics of ovary locule inheritance. Among these, 190 plants had multilocular ovaries, whereas the remaining 76 had bilocule ovaries. This distribution closely matched the expected 3:1 ratio (multilocules to bilocules), which is characteristic of Mendelian inheritance patterns. The chi-square value of only 1.6 confirmed the genetic simplicity, implying that ovarian locule inheritance is primarily governed by a single dominant gene, with slight variances ascribed to stochastic influences. Fig.2 showed the frequency of multilocular and bilocular ovary genotypes in various generations giving out clear picture of inheritance pattern

•Backcross BC1P1 (F1 x NDYS): All 360 plants in the backcross generation with NDYS had multilocular ovaries. This unmistakable result serves as a resounding reinforcement of NDYS's dominance in this environment.

Backcross BC1P2 (F1 x Pant Girija): In contrast, the Pant Girija backcross revealed a 1:1 segregation of multilocules to bilocules, indicating codominance of alleles from both parents. When alleles from both parents are present, this interesting genetic interplay reveals a complex control of ovarian locule inheritance.

Table 3: Inheritance pattern of ovary locules in different generation of Pant pili sarson1 (multilocule) x Pant girija (bilocule)

Generation

Total no. of plants

Expected frequency

Observed frequency

Expected ratio

X²cal

X2

tab (0.05,

1 df)

Multilocule

Bilocule

Multilocule

Bilocule

F

1

40

0

20

0

F

2

300

225

75

230

70

3:1

0.44

3.84

BC P (F x

1 1 1

Pant pili sarson 1)

370

0

370

0

1:0

0.00

3.84

BC₁P₂ (F x

1

Pant girija)

360

180

175

185

1:1

0.28

3.84

Cross 3 -Inheritance pattern of ovary locules in different generations of Pant pili sarson1 (multilocule) x Pant girija (bilocule)

In this study, we look into the observed ratios; table 3 clearly indicates the viewpoint that is critical for plant breeders:

• F1 generation: Every single plant in the first F1 generation had multilocule ovaries. This clear result indicates that the multilocule characteristic has complete dominance. In this case, the measured ratio was 100% multilocule to 0% bilocule, revealing a clear genetic picture.

• F2 Generation: The F2 generation revealed a fascinating genetic segregation pattern. 75 plants in the overall population had multilocule ovaries, while 70 had bilocule ovaries. This distribution followed the conventional Mendelian ratio of three to one (multilocules to bilocules). This finding demonstrates that ovary locule inheritance is governed by a single dominant gene, which is critical information for plant breeders.

• Backcross with Pant pili sarson 1 (BC P1): Every single plant displayed multilocule ovaries in the backcross generation with Pant pili sarson 1. This unequivocal result supports the multilocule trait's total dominance, completely agreeing with the reported 100% multilocule ratio.

• Backcross with Pant girija (BC1P2): The observed ratio in the backcross involving Pant girija was an even split, with 50% of plants displaying multilocule ovaries and the remaining 50% displaying bilocule ovaries. This 1:1 ratio (multilocules to bilocules) demonstrates that the multilocule characteristic remains dominant even in this genetic context.

Geneticists and plant breeders could benefit from the discoveries of our investigation into ovary locule inheritance in Brassica. Being well-informed on the genetic foundation of features like ovary locules is crucial in bettering crop-quality endeavors.Observed in the F1 generation was the prevalence of multilocular ovaries, indicating the practical benefit of this dominant trait in breeding initiatives. If breeders have a desire to cultivate varieties with such traits, they can utilize this information to choose parents with multilocular capabilities, resulting in increased yields of fruits or seeds that can be advantageous for specific species of Brassica.

In the second generation, F2, for multilocules and bilocules they stuck to the 3:1 segregation ratio which confirms that there is only one dominant gene that controls ovary locules. There were some slight divergences from what was expected, but this is typical for genetic studies and could be caused by things in their environment or small sample sizes. Despite any inaccuracies, because there is only one dominant gene present, choosing which traits to select in breeding programs becomes simpler making it easier for breeders to accurately forecast and control ovary locule characteristics.

Genetic control of ovary locules has been advanced by the backcross findings. A trustworthy strategy to keep multilocularity was exhibited by BC1P1, which featured complete dominance of multilocular ovaries. In contrast, BC1P2 showed codominance between multilocular and bilocular alleles. This data is vital for breeders hoping to cultivate Brassica varieties with varying ovary locule phenotypes or test out fresh trait combinations. the researchers found that brassica rapa multilocular inheritance was governed by recessive gene (He etal., 2003), the multilocular trait in Brassica rapa (AA), a diploid, is controlled by a recessive nuclear gene (Fan et al., 2014), whereas in Brassica juncea (AABB), an allotetraploid, it is controlled by two independently inherited recessive nuclear genes (Xiao et al., 2013; Xu et al., 2014). but my results were contrary and new insights were found the Mendelian inheritance pattern uncovered in this study provides valuable insights for plant breeders seeking to manipulate ovary locule traits in Brassica crops. The presence of a single dominant gene simplifies the breeding process and allows for precise trait selection. By leveraging this genetic knowledge, breeders can develop Brassica varieties with desired ovary locule characteristics, ultimately contributing to improved crop yields and agricultural sustainability. Further genetic research may unveil the specific genes responsible for this trait, paving the way for more targeted breeding strategies in the future.

In conclusion, the findings from our investigation into ovary locule inheritance in Brassica represent a significant advancement in the field of plant breeding. The discovery of a single dominant gene governing multilocular ovaries simplifies the breeding process, enabling breeders to reliably select parent plants with this desirable trait. The confirmation of a 3:1 segregation ratio in the F2 generation underscores the genetic stability of this trait, despite minor deviations common in genetic studies. Additionally, the insights gained from the backcross strategies provide breeders with flexible options for cultivating Brassica varieties with diverse ovary locule phenotypes. This genetic knowledge empowers breeders to make precise trait selections, ultimately contributing to the development of Brassica crops tailored to specific agricultural needs, leading to improved crop yields and sustainability. As we move forward, further genetic research may unveil the specific genes responsible for this trait, opening up possibilities for even more targeted breeding strategies in the future.

Acknowledgements

Charu bisht , amit kumar gaur have edited and prepared the manuscript and analysed the data , Birendra prasad , usha pant and s.k. verma have guided in experiment outline and experimental design implementation , neha panwar and Shubham gupta have contributed in material preparation and crossing of plants , sivendra joshi and himanshu prasad have helped in taking data phenotypically , Yashpal singh bisht and harshdeep have contributed in manuscript editing and revison

Funding

“The authors declare that no funds, grants, or other support were received during the preparation of this manuscript.”

Competing Interests

“The authors have no relevant financial or non-financial interests to disclose.”

Author contributions

Charu bisht , amit kumar gaur have edited and prepared the manuscript and analysed the data , Birendra prasad , usha pant and s.k. verma have guided in experiment outline and experimental design implementation , neha panwar and Shubham gupta have contributed in material preparation and crossing of plants , sivendra joshi and himanshu prasad have helped in taking data phenotypically , Yashpal singh bisht and harshdeep have contributed in manuscript editing and revison

Data availability

The datasets generated during and/or analysed during the current study are not publicly available Privacy and Ethical Concerns but are however available from corresponding author after reasonable request

Xu, P, Wang, X, Dai, S, et al. The multilocular trait of rapeseed is ideal for high-yield breeding. Plant Breed. 2021; 140: 65–73. https://doi.org/10.1111/pbr.12880
Katiyar, R. K., Chamola, R., & Chopra, V. L. (1998). Tetralocular mustard, Brassica juncea: New promising variability through interspecific hybridization. Plant Breeding, 117, 398–399. https://doi.org/10.1111/j.1439-0523.1998.tb01962.x
Lv, Z. W., Xu, P., Zhang, X. X., Wen, J., Yi, B., Ma, C. Z., & Shen, J. X. (2012). Primary study on anatomic and genetic analyses of multi-loculus in Brassica juncea. Chinese Journal of Oil Crop Sciences, 34(5), 461–466.
Zhao, H. C., Du, D. Z., Liu, Q. Y., Li, X. P., Yu, Q. L., & Fu, Z. (2003). Performance in main characteristics of multilocular Brassica juncea. Acta Agriculturae Boreali-occidentalis Sinica, 12(3), 62–64.
Zhu, L. X., Zhang, X. D., Fu, T. D., & Shen, J. X. (2010). Analysis of yield and disease resistance traits of new winter rapeseed variety in the past twenty years in China. Chinese Agricultural Science Bulletin, 26(24), 375–380.
Song, X., Liu, F. L., Zheng, X. K., Lu, G. Y., Fu, G. P., & Cheng, Y. (2010). Correlation analysis between agronomic traits and yield of raoeseed (Brassica napus L.) for high-density planting. Scientia Agricultura Sinica, 43(9), 1800–1806.
Xiao, L., Zhao, H. Y., Zhao, Z., Du, D. Z., Xu, L., Yao, Y. M., & Zhao, H. C. (2013). Genetic and physical fne mapping of a multilocular gene Bjln1 in Brassica juncea to a 208-kb region. Molecular Breeding, 32, 373–383.
Fan, C. C., Wu, Y. D., Yang, Q. Y., Yang, Y., Meng, Q. W., Zhang, K. Q., & Zhou, Y. M. (2014). A novel single-nucleotide mutation in a CLAVATA3 gene homologue controls a multilocular silique trait in Brassica rapa L. Molecular Plant, 7(12), 1788–1792.
Liu, H. L. (1987). Practical cultivation in rapeseed, 1st ed. : Shanghai Science and Technology Press.
Xu, P., Lv, Z., Zhang, X., Wang, X., Pu, Y., Wang, H., Yi, B., Wen, J., Ma, C., Tu, J., Fu, T., & Shen, J. (2014). Identification of molecular markers linked to trilocular gene (mc1) in Brassica juncea L. Molecular Breeding, 33, 425–434. https://doi.org/10.1007/s11032-013-9960-7
He, Y. T., Long, W. H., Hu, J. P., Fu, T. D., Li, D. R., Chen, B. Y., & Tu, J. X. (2003). Anatomic and genetic studies on multicapsular character in Brassica campestris L. Chinese Journal of Oil Crop Scieves, 25(1), 1–4.

No competing interests reported.

New insights on inheritance of multilocular trait in yellow sarson Rare inheritance studies in yellow sarson for petalous and apetalous trait

Status:

Version 1

Abstract

Figures

Introduction

Materials and Methods

Chi-Square Analysis:

Result

Discussion

Conclusion

Declarations

References

Additional Declarations

Status:

Version 1