Durum-21: A New High-Yielding and Good Quality Durum Wheat Variety Suitable for Pasta Production

: Durum-21 (D-21) is a high-yielding, disease resistant with better-quality traits variety, developed by Wheat Research Institute Faisalabad. This variety is mainly developed for industrial purposes for pasta production. Worldwide, durum wheat is utilized for pasta production; but in Pakistan, due to a lack of research work and non-availability of quality seeds of durum wheat, bread wheat is being utilized for pasta production. D-21 is developed with the breeding code of D-21 having parentage of FKN/3/2*FR//KAD/GB/4/BB/CHA/5/AS-2002 with pedigree as PB20733-1a-2a-2a-0a-0a-19a-0a. The candidate line D-21 was developed by crossing a germplasm accession with approved bread wheat variety AS-02. The genotype was further evaluated over multiple locations in Punjab Pakistan for yield and yield-related attributes in the station, provincial, and national uniform durum yield trials executed by Wheat Research Institute (WRI), Faisalabad during 2015-20. The promising line out yielded the two commercial check varieties D-97 and Fsd-2008 by 1.42 % in the provincial yield trial and 4.2 % in the national yield trial. D-21 had desirably medium to tall plant height (96-100 cm) without anthocyanin pigment. It has erected to semi-erect growth habit at the seedling stage. Its color is green with medium waxiness on stem and yellowish-white at maturity. Its 1000-grain weight ranged from 38.9 to 39 g while the test weight remained from 69 to 78.5 g. The protein contents were 13.1 to 14.95 %; which is higher than the two checks (D-97 and Fsd-2008). Due to its better grain yield and promising nutritional and quality parameters, it was approved in the year 2021 for cultivation all over the country.


INTRODUCTION
Durum wheat (Triticum turgidum L.) is a tetraploid species of wheat that is primarily grown for industrial purposes.It is mainly grown in Mediterranean countries, including the Middle East, North America, and North Africa [1] Durum wheat offers a great advantage over bread wheat in a number of aspects.Durum wheat has A and B genomes with 28 chromosomes while bread wheat contains A, B, and D genomes with 46 chromosomes [2] Durum wheat is much harder than bread wheat which requires more thorough grinding to produce semolina and flour.Durum wheat dough contains a strong viscoelastic protein complex known as gluten which makes it more suitable for pasta production, on the other hand, bread wheat is mainly utilized for domestic purposes to make bread [3].A typical durum wheat grain is vitreous, very hard, amber in colour, and contains 2-3 % more protein and gluten content as compared to bread wheat [4].Besides high protein and gluten content it is also rich in carotenoid, folate, iron, calcium, and dietary fibre [5].Durum wheat was grown on an area of over 16 million hectares with an annual global production of over 38 million tonnes [6].The largest producing countries of durum wheat are including Turkey and Canada with an estimated area of more than 2 million ha of each followed by Italy, Algeria, and India [7].Due to its economic importance and unique properties, it is used to make a wide range of food products including semolina, pasta, noodles, burghul wheat, Couscous, and desserts.Durum wheat is milled into a small granular form that is known as semolina and that is mainly utilized for pasta production [8].
Different value-addition industries of wheat require specific quality wheat grains.The most widely used wheat in pasta products is durum wheat [9].The international food industry, involved in pasta products uses durum wheat flour for making quality products.Pakistan has a transforming economy hosting many western food chains across the country.Changing lifestyles and tastes of the population suggest increasing demand for pasta products.Currently, durum wheat is being imported by all pasta industry stakeholders on account of the non-availability of high-yielding durum wheat variety and milling units.Due to increasing demand for pasta products and their premium price, milling units are being established across the country and research work has been initiated for the development of good quality durum variety.The provision of high-quality durum variety will help to reduce the import bill through local production of durum wheat flour.The current research work was conducted to develop high-yielding, better quality, and disease-resistant durum wheat variety that can be utilized in industry for pasta production.

MATERIALS AND METHODS
The present research work was conducted at Wheat Research Institute, Faisalabad Pakistan along with various locations in the province of Punjab during 2015-2020.The D-21 has parentage of FKN/3/2*FR//KAD/GB/4/BB/CHA/5/AS-2002 with pedigree as PB20733-1a-2a-2a-0a-0a-19a-0a.Durum wheat line D-21 is developed by crossing a germplasm accession with approved bread wheat variety AS-02.The proposed variety has an edge in yield over Durum-97 with genetic resistance to diseases.This variety is suitable for planting from 1 st to 20 th November in Punjab province.The D-21 was evaluated for higher grain yield, disease resistance, and other attributes at station yield trials.Station yields trials further consist of preliminary and regular yield trials.Both these trials were conducted at WRI, Faisalabad.Based on higher yield performance in generation trials D-21 was tested in a preliminary yield trial conducted during 2016-17.The trial was consisting of 10 entries along with one check variety D-97 following RCBD design.The experimental plot size was maintained at 8.1 m 2 with 6 rows and three replications.The R×R distance was kept at 27 cm and the length of each row was maintained by 5m.This line is then promoted into a regular yield trial that was comprised of 16 entries along with 2 check varieties Fsd -2008 and D-97.The trial was laid out under RCBD, by maintaining the net plot size of 8.1 m 2 during 2017-18.The promising line was then promoted into Provincial Uniform Durum Yield Trial (PUDYT) to check the adaptability and stability over multiple locations throughout the province of Punjab.The D-21 was compared with two local checks Fsd-08 and D-97 in Provincial Uniform Durum Yield Trial.This genotype was again sent in National Uniform Durum Yield Trial (NUDYT) in the next two consecutive years  to test the adaptability and yield stability of a mega environment throughout Pakistan.The grains of D-21 were sent to Crop Disease Research Institute (CDRI), NARC, Islamabad to screen out against the indices of leaf and yellow rust during the NUDYT testing years.All other management practices were accomplished as per crop recommendation.Seed samples of the candidate line were taken from (PUDYT 2017-18) for the assessment of the quality analysis from Cereal Technology Laboratory WRI, Faisalabad according to the standard protocol of American chemists [10] & [11].The crop development stages were observed continuously until crop maturity and grain retentions in mature spike during every crop cycle.The brief development history of D-21 is mentioned in Table 1.

Preliminary Yield Trial (2015-16)
The preliminary yield trial was conducted at Wheat Research Institute Faisalabad during 2015-16.Ten (10) entries along with three replications were tested and compared with one local check variety durum-97 as shown in Table 2.The advanced line D-21 yielded 3931 kg/ha -1 .It performed better than the check variety in the preliminary yield trial and gave 8.90 % higher yield than D-97.Therefore, it was re-evaluated for yield and stability in regular yield trials (B-trial).

Regular Yield Trial (2016-17)
The regular yield trial was conducted during 2016-17 at WRI, Faisalabad to check the yield performance of candidate line D-21.The results of this trial indicated that the advanced line D-21 produced 3856 kg ha -1 with an 8.90 % higher yield than D 97.Moreover, the disease data also indicated that the advanced line was ultimately resistant to leaf and yellow rusts as mentioned in Table 2. Therefore, it was promoted to Punjab Uniform Durum Yield Trial during 2017-18 for yield stability and adaptability evaluation.

Punjab Uniform Wheat Yield Trial (2017-18)
Based on the better performance of two consecutive years in station yield trial, the advanced line D-21 was tested for wider adaptability across a mega environment in a provincial uniform durum yield trial (PUDYT) over 20 locations in irrigated areas of Punjab during 2017-18.The overall yield performance of different advanced lines at various locations in Punjab is given in Table 3.The proposed line D-21 out yielded the check variety D-97 by 1.45 % at different locations in Punjab.Moreover, the candidate line also showed resistance against leaf and yellow rust.On the basis of tabulated and diseased screening data, this line was further tested in National Uniform Durum Yield Trial (NUDYT) during 2018-19.

National Uniform Durum Yield Trial
A good variety is that which perform better with respect to yield and yield-related attributes under a diverse environment.Development of higher  4  and 5).

Agronomic Trials
To

Disease Screening Studies
The advanced line D-21 was screened against leaf and yellow rust by Cereal Disease Research Institute Islamabad (CDRI) by the inclusion in National Wheat Disease Screening Nursery (NWDSN) at various locations for two consecutive years 2018-19 and 2019-20.The advanced line D-21 showed high resistance against yellow and leaf rust for two consecutive years.Moreover, it also showed zero % terminal reaction as compared to commercial check variety which showed high susceptibility with terminal rust reaction of more than 50 S in 2018-19 and more than 20 S in 2019-20 as illustrated in tables 9 and 10.The obtained disease screening results of line D-21 revealed that this genotype was resistant to yellow and leaf rust and could be used to develop leaf and yellow rust resistance sources in future breeding programs.

Quality Related Characteristics
Different quality-related parameters of D-21 were evaluated.Durum wheat is mainly utilized in the industry for pasta production as it contains more amount of gluten and protein content.High percentage of gluten and protein in durum grain makes it better for pasta production.Its 1000-grain weight was 38.9-39 g and the test weight remained 69-78.5 g.The protein contents were 13.1 to 14.95 % which was higher than the two checks D-97 and Fsd-2008.Moreover, its pasta and noodles making quality parameters were also promising as compared to local checks variety Fsd-2008 and D-97 (table 11).

Botanical Attributes of D-21
The new variety D-21 had desirably medium to tall (96-100 cm).Anthocyanin pigment was absent at seedling as well as at maturity.It has an erect to semi-erect growth habit.Its color is green with medium waxiness on the stem and yellowish-white at maturity.Its stem is stiff enough that provide resistance against lodging.A number of tillers vary from 350 to 450 m 2 .It contains a waxy flag leaf with an erect orientation of 27 to 30 cm in length and 1.9 to 2.1 cm in width.Hairiness auricle was present with weak anthocyanin pigmentation.It has awns of medium length, shattering resistant, dense ear with small to medium in size having 55-65 seeds per ear.Rachis is 10-12 cm in length with 16-18 segments.It takes 110-120 days for heading and it matures in 150-60 days.Its glume length is about 13.5-14.5 and its width is 3.8-4.0cm with strong attachment.Shoulder of the glume was narrow to medium and glume beak was straight and its pubescence was absent.The glume surface was smooth and without internal hairs and imprints.It has a medium sized seed with an ovate shape and amber in color with a medium brush and opaque surface with an intermediate groove.The germ size of the seed was medium.Its bread and chapattimaking quality were good to very good as mentioned in Table 12.Moreover, it is highly resistant against the leaf and yellow rust races and gave good yield under different locations in Punjab and Pakistan.
It also showed a good response against fertilizer applications having better adjustment to different ecological zones.Similar observations were reported by Nilusha et al. [9].Botanical description of Durum-21 is given in Table 12 and a pictorial view of the plant, grain, and spike is presented in Figure 1.

CONCLUSION
Wheat Research Institute Faisalabad is one of the renowned research institutes of the world as it is

Sowing time
November 01 to December 10 12.5 No. of segments 16-18

CONFLICT OF INTEREST
All the authors declared no conflict of interest.

Fig. 2 .
Fig. 2. Dendrogram of different Durum on the basis of similarity

Fig. 2 .
Fig. 2. Dendrogram of different Durum on the basis of similarity

Table 2 .
Grain yield of "D-21" in station yield trials

Table 6 .
Grain yield of "D-21" in sowing date trials

Table 7 .
optimize sowing time, seed rate and fertilizer levels of advanced line D-21, the agronomic trials were conducted at WRI, Faisalabad during 2018-20.The promising line D-21 performed better with respect to planting time with a notable margin of 9.7 % in 2018-19 and 12.8 % again in 2019-20 over the check varieties as mentioned in Table6.To assess the best seed rate for D-21 another agronomic trial was performed at WRI, Faisalabad.The advanced line D-21 performed better at the seed rate of 150 Kg ha -1 in both the years.It out yielded the local checks by a margin of 2.8 and 4.7 % respectively as indicated in Table7.The third agronomic trial was conducted related to fertilizer application.To optimize the level of fertilizers, Grain yield of "D-21" in seed rate trials

Table 8 .
Yield response of D-21 to different fertilizer doses

Table 9 .
Yellow rust data of LDSN at different locations

Table 10 .
Leaf rust data of LDSN at different locations