After reading this article you will learn about:- 1. Origin of Pea 2. Botany of Pea 3. Distribution 4. Qualitative Genes 5. Breeding Goals 6. Genetic Resources 7. Important Donors for Pea Breeding Programme 8. Breeding Procedure 8. Molecular Markers 9. Integration of Biotechnology in Conventional Pea Breeding 10. Snap Pea 11. Vegetable Pea Varieties 12. Field Pea Cultivars 13. Future Prospects.
Origin of Pea:
The geographical region comprising of Central Asia, the Near East, Abyssinia, and the Mediterranean is considered as center of origin based on genetic diversity. According to Blixt (1970), the Mediterranean is the primary centre of diversity with secondary centres in Ethiopia and the Near East.
The genus Pisum comprises of only a small number of taxa. All taxa within Pisum are diploid (2n = 2x = 14) and the majority are fully inter-crossable with a few being more difficult, but possible. Pisum humile syn. syriacum is considered a possible candidate as progenitor, as it resembles closely to the cultivated form. There has been introgression to cultivated types from P. humile and P. elatius.
The characters associated with domestication are as follows:
Botany of Pea:
Pea is an annual herbaceous plant. It has a tap root system. Stems are slender, usually single, and upright in growth. Leaves are pinnately compound with two to several leaflets. The rachis terminates in a simple or branched tendril. There are large stipules at the base of leaf.
The plant may be single stemmed or many axillary stems may originate at the cotyledonary node or any superior node, especially if the apical growing point is destroyed, leaflets of a pair are opposite or slightly alternate. The lower leaflets are larger than the upper leaflets. The margins of leaflets and stipules may be entire or serrated.
The inflorescence is raceme arising from the axil of a leaf. The lowest node at which flower initiation occurs, is normally constant under a given set of conditions and is used in classifying the varieties into early and late types.
Most early cultivars produce the first flower from nodes 5 to 11 and the late cultivars start flowering at about nodes 13 to 15. Early cultivars are often single flowered or bear some single and some double flowers. Late cultivars are usually double/triple flowered.
The flowers are typical papilionaceous with green calyx comprising of five united sepals, five petals (one standard, two wings and two keels). The stamens are in diadelphous (9+1) condition. Nine filaments are fused to form a staminal tube, while the tenth is free throughout its length.
The gynoecium is monocarpellary, with ovules (up to 13) alternately attached to the two placentas. Style normally bends at right angle to the ovary. Stigma is sticky. Pea is strictly self-pollinated in nature. Stigma is receptive to pollen from several days prior to anthesis until 1 day or more after the flower wilts.
Pollen is viable from the time anthers dehisce till several days thereafter. For emasculation, the flower bud chosen should have developed to the stage just before anther dehiscence, indicated by extension of petals beyond sepals. Flowers can be emasculated at any time.
The first step in emasculation is to tear away with the forceps the tip of the sepal from in front of the keel. The forefinger is positioned behind the flower and thumb in front and a light pressure is applied. This spreads the standard and wings to expose the keel. The exposed keel is slit-open by tips of forceps. Pressure can be applied by the thumb and finger on keel for increased exposure of the pistil and stamens. The 10 stamens are pulled out.
Pollen can be obtained throughout the day, preferably from a freshly opened flower. For pollen collection, it is more convenient to pick the male flowers, remove the standard and wings, pull back the keel so that the style protrudes and use the pollen covered stylar brush as an applicator to transfer the pollen to the stigma of the emasculated bud.
Older flowers and other flower buds not used in crossing are removed from the peduncle to increase the pod set after crossing. Normally emasculatioin is done in afternoon followed by pollination next forenoon/morning. The somatic chromosome number of peas is 14 . The translocations and other chromosome arrangements are common.
The seven characters studied by Mendel have been mapped as indicated below:
(i) The shape of mature seeds, smooth/wrinkled (R/r), in chromosome 7
(ii) Seed colour, yellow/green (I/i), in chromosome 1
(iii) Flower colour, purple/violet or white (A/a), in chromosome 1
(iv) Mature pods, smooth and expanded/wrinkled and indented (V/v) in chromosome 4
(v) Colour of unripe pods, green/yellow (Gp/gp), in chromosome 5
(vi) Inflorescence, axillary/terminal (Fa/fa), in chromosome 4
(vii) Plant height, tall/dwarf (Le/le) in chromosome 4
Thus, Mendel probably dealt with the genes a and i in chromosome l, le, fa and v in chromosome 4, gp in chromosome 5, and r in chromosome 7. One may ask as to why he did not run into the complication of linkage while formulating the law of independent assortment.
The answer is that with respect to a and i in chromosome 1 and fa in relation to le and v in chromosome 4, these genes are so distant, that linkage is not realized. The only two genes which could have shown linkage were le and v. As far as is known, Mendel did not study the simultaneous segregation in these two.
Distribution of Pea:
Peas (Pisum sativum L., 2n = 2x = 14) are consumed as fresh vegetables or dry seeds throughout the world. In India, peas are grown as winter vegetable in plains and as summer vegetable in the hills. As field pea, it occupies about 0.45 m ha area in India, accounting for only about 2% of the total pulse area.
About 90% of field peas area and production is limited to Uttar Pradesh alone. In general, area under vegetable peas is on increase. The acreage of vegetable pea in India is 3.5 lac ha with 2.92 million tons of green pod production. Major production states are UP, Bihar Haryana, Punjab, Himachal Pradesh, Orissa and Karnataka.
It is worthwhile to mention that large scale production of vegetable peas for international market is still based largely on old varieties. Arkel introduced in India in 1970s still holds ground and is a household name in vegetable pea growers and consumers.
Qualitative Genes of Pea:
Significant contributions on qualitative genetics of peas have been made by several scientists. Blixt (1974) has given a list of 324 qualitative genes. A partial listing of genes useful in breeding programme has been compiled by Gritton (1986). Table 15.1 is adapted from this. Breeding Goals of Pea:
1. High green pod yield
2. Long, attractive green pods with more seeds/pod (9-12 seeds)
4. High shelling percentage
5. Specific maturity (early, mid)
6. Suitable for freezing and canning
7. Resistant/tolerant to frost
8. Resistant to diseases, namely:
(i) Downy mildew (Peronospora viciae (Berk.) de Bary)
(ii) Powdery mildew (Erysiphe polygoni DC)
(iii) Rust (Uromyces viciae – fabes (Pers). Schroet, and U. pisi (Pers.) Wint.)
(iv) Wilt (Fusarium oxysporum Schl. f. sp. pisi (van Hall) Synd. & Hans.)
9. Resistance to insects, namely:
(i) Leaf miner
(iv) Pea stem fly
The primary characters used for grouping of varieties include traits related to seed and pod types, maturity groups and plant height.
A useful point of reference list of characters and descriptors used in the UPOV guidelines is given in Table 15.2:
Genetic Resources of Pea:
A large number of ex-situ germplasm collections have been reported around the world in public domain as compiled by Ambrose (2008) and given in Table 15.3.
These centers have been actively collaborating with each other in PGR management of peas. In absence of CGIAR funded international agricultural research center with global mandate on peas, an international consortium for pea genetic resources (Pea GRIC) has been formed that links key collections in Europe, USA, ICARDA and Australia.
In India, about 2000 pea germplasm accessions are conserved at NBGPGR, New Delhi, IIVR, Varanasi and IIPR, Kanpur, Besides, a few state agricultural universities rich in vegetable pea germplasm are G.B. Pant University of Agric. and Technology, Pantnagar, Punjab Agricultural University, Ludhiana, Haryana Agriculture University, Hisar, JNKVV, Jabalpur and Indian Agric.Res. Inst., New Delhi.
Important Donors for Pea Breeding Programme:
Singh (1991, 1995) has compiled extensive information on genetics and breeding of peas including listing of superior lines with multiple disease resistance in pulse crops. Kalloo (1993) and Narsinghani and Tewari (1993) have also given detailed accounts of pea breeding.
A few examples of donors on peas are as follows:
Earliness: Asauji, Lucknow, Bonia, Hans, EC 3
More pods/plant: PL P 26, 50, 69, 179, 279, 496
Long pods: EC 109171, 109176, 109190, 109195
Bold pods: EC 4103, 6185, 95924
Powdery mildew: EC 326, 42959, 109190, 109196, T 10, P 185, P 288, PC 6578, B 4048, P 6587, P 6588, BHU 159, EC 42959, IC 4604, JP 501, VP 7906
Wilt : Early Perfection, Bonneville, PL 43, 124, 6101, Glacier
Rust: PJ 207508, 222117, EC 109188, EC 42959, IC 4604, PJ 207508, JP Batri Brown 3, JP Batri Brown 4
Pea mosaic : American Wonder, Perfecion Canner’s Gem, Dwarf White Sugar, Little Marvel
Leaf miner : EC 16704, 21711, 25173
Pea stem fly (tolerant): Bonneville, Asaugi, Boach Sel., GC 141, IP 3 (Pant Uphar), Dwarf Gray Sugar, T 10, T 163
Breeding Procedures of Pea:
Peas are self-pollinated due to cleistogamy and accordingly, the common breeding procedures applicable to self-pollinated crops viz. pedigree, bulk, single seed descent (SSD), back-cross and mutation breeding are used in pea breeding.
Single seed descent method is now becoming common in peas. This is particularly, useful in those situations where selected better lines are intercrossed. F1 plants are grown to produce 500 or more F2 seeds.
One seed is harvested from each F2 plant and the harvested seeds are bulked to plant F3. This procedure continues till F5 in which phenotypically, superior individual plants are selected for future plant to progeny planting and evaluation. A major advantage of this method is, that, it can be carried out with less resources and the rapid advancement of generations is possible in field and glass-house/off season-nursery.
While advancing the generations, selection for highly heritable traits is practiced frequently in early generations, before lines are grown out as small plots in F4/F5 generation. Shuttle breeding is also practised in peas where alternate generations (like F3 and F5) are grown at off-site locations. For example, in India alternate generations can be grown in late kharif in Pune and Nasik in Maharashtra and followed by winter season in northern plains.
In this way, 2 generations can be grown in a year. There is widespread use of SSD utilizing glasshouses or plant growth chambers to speed-up early generations while also maintaining a wider level of variability between lines before growing plant to progeny rows for field evaluation and selection. Bulk selection is also used by some breeders.
In garden pea number of green pods/plant, green pod weight, pod length and number of seeds/pod have been shown to be the major yield components affecting the green pod yield. These yield components usually do not show component compensation effect and therefore, simultaneous improvement for these characters should be possible.
Prospects of mutation breeding in peas have been discussed by Jaranowski and Micke (1985). A dose of 10-15 krad of gamma rays is appropriate for seeds. A good criterion of effectiveness of any mutagen is germination reduction, not exceeding 50% for gamma radiation, better only 30% for neutrons and certain chemical mutagens.
Stronger germination reduction may result for a high number of chromosomal aberrations and this in turn will lead to high sterility. Among chemicals, EMS, NEU, EI, NMU and sodium azide seem to be the most efficient mutagens for peas.
Chemical compounds are applied as water solutions and seeds are usually presoaked for 12-16 hours. Presoaking facilitates the penetration of the mutagen into the tissues. The optimum temperature and duration are 21-24°C and 2-4 hours, respectively.
Recommended concentrations of certain chemical mutagens for pea seeds are:
EMS : 0.05 – 0.3%
NEU : 0.20 – 0.40 millimole
EI : 0.05 – 0.15%
NMH : 0.01 – 0.03%
DES : 0.03%
The solutions should be fresh prepared and buffered to pH 5-6. All the mutagenic compounds are toxic and some are very carcinogenic and should be handled with extreme care. The probability of obtaining a favourable variant/mutant (as in other breeding approaches) is strongly related to the size of the plant population screened.
Treating only a few hundred seeds can hardly be expected to give positive results. Approximately, 1000 surviving and fertile plants in M; generation are certainly the minimum, considering that even the effective mutagen treatments may lead to only one mutation per locus in 100000 cells.
M1 generation should be grown under optimum conditions. Each M1 plant should be harvested individually for growing M2 progenies. If M1 generation is large, a single pod or even a single seed/M1 plant may be harvested.
Starting with the M2 generation, the optimum methods are very similar to those used for hybridization programme from F2 onwards. Most reliable is pedigree selection. Bulk handling followed by pedigree method is also recommended.
However, it should be recognized that in spite of lot of efforts on mutation breeding in peas, in Sweden, Italy, Germany, Poland and Bulgaria, hardly a few mutations have been released as commercial cultivars. Thus, it is clear that mutants have provided a significant range of variation, but that is widely represented in modem day pea breeding, materials.
As a matter of fact, applied mutation breeding is certainly less charming and is on decline, although one can find numerous mutagenesis programmes in public sector research. In India, this facility is easily available in Nuclear Agric. and Biotech Division of Bhaba Atomic Research Centre, Trombay, Mumbai.
A major step in producing a plant model more suited to the crop environment was made by B. Snoad who introduced the ‘st’ gene for reduced stipule size and the ‘af’ gene, which substitutes tendrils for leaflets. A detailed review on this has been written by Hedley and Ambrose (1981). Plants with the genetic constitution ‘af af st st’ have acquired the descriptive name of ‘leafless’.
The main advantage of the ‘leafless’ pea is its improved standing ability due to its greater number of tendrils. The risk of lodging is reduced and the crop can be more easily harvested. The improved canopy structure may also allow the crop to dry more rapidly with a reduced risk of disease.
Comparisons between near-isogenic leafed and leafless lines grown as spaced pot plants, however, have shown that the yield per plant of the mutant is reduced relative to that of the leafed plant.
However, there are also reports where no significant difference in yield per plant between comparable near-isogenic lines has been observed when grown in randomized plots. More research is still needed regarding these plant types but it seems that they do not offer yield advantage as such.
It is convenient to plant spreader rows of a highly susceptible cultivar for field screening against powdery mildew and rust. Plants can also be inoculated by dusting the powdery mildew spores from freshly infected leaves. Similarly, for rust, spore suspensions prepared from infected plants can be sprayed. Screening for wilt will be more effective in the ‘sick’ plots.
Considering the fact that powdery mildew is a serious disease of pea and for which new good resistant donors are available, a typical backcross breeding approach as applicable to a character governed by a single recessive gene (powdery mildew in pea is under a single recessive gene) as outlined by Gritton (1986) has been shown in Fig. 15.4.
Molecular Markers in Pea:
Since the development of the polymerase chain reaction (PCR) in generating random amplified polymorphic DNA in 1990, this technique has been found valuable in the construction of genetic maps in several species and in production of genetic markers linked to specific phenotypic traits in particular using bulked segregant pools. RAPD technique became popular because of its simplicity and ease of use.
Laucou et al. (1998) constructed a genetic linkage map of Pisum sativum L. based primarily on RAPD markers that were carefully selected for their reproducibility and scored in a population of 139 recombinant inbred lines (RILs). The mapping population was derived from a cross between a protein-rich dry-seed cultivar ‘Terese’ and an increased branching mutant (K 586) obtained from the pea cultivar ‘Torsdag’.
The map currently comprises nine linkage groups with two groups comprising only 6 markers (n = 7 in pea) and covers 1139 cM. This RAPD-based map has been aligned with the map based on the (J1281 x J1399) RILs population that includes 355 markers in seven linkage groups covering 1881 cM.
For this alignment 7 RFLPs, 23 RAPD markers, the morphological marker le and the PCR marker corresponding to the gene Uni were used as common markers and scored in both populations. Genes for which linked markers have been reported in the pea are listed in Table 15.4.
McClendon et al. (2002) identified DNA markers linked to fusarium wilt race 1 resistance in pea. Eighty recombinant inbred lines (RILs) from the cross of Green Arrow (resistant) and PI 179449 (susceptible) were developed through single-seed descent, and screened for disease reaction in race 1 infested field soil and the greenhouse using single-isolate inoculum.
The RILs segregated 38 resistant and 42 susceptible fitting the expected 1: 1 segregation ratio for a single dominant gene (chi2 = 0.200). Bulk segregant analysis (BSA) was used to screen 64 amplified fragment length polymorphism (AFLP) primer pairs and previously mapped random amplified’ polymorphic DNA (RAPD) primers to identify candidate markers. Eight AFLP primer pairs and 15 RAPD primers were used to screen the RIL mapping population and generate a linkage map.
One AFLP marker, ACG: CAT_222, was within 1.4 cM of the Fw gene. Two other markers, AFLP marker ACC : CTG₋159 at 2.6 cM linked to the susceptible allele, and RAPD marker Y15 1050 at 4.6 cM linked to the resistant allele, were also identified. The probability of correctly identifying resistant lines to fusarium wilt race 1, with DNA marker ACG : CAT_222, is 96%. These markers will be useful for marker assisted breeding in applied pea breeding programs.
Marker assisted selection (MAS) is now being integrated in on-going conventional pea breeding programmes. MAS is particularly, useful to speed-up selection for those traits that express late in plant development. Such target traits include resistance for diseases and even lodging and seed characters.
Isozyme marker alcohol dehydrogenase (Adh 1) has been shown to be linked with resistance to pea enation virus (En.). Two recent examples related to disease resistance are development of PCR markers designed from cDNA-AFLP fragments providing tight linkage to genes (subm-1. and mo) conferring resistance to pea seed borne mosaic virus and an SSR marker suitable for resistance to powdery mildew of peas as mentioned by Ambrose (2008). QTLs for lodging resistance have been reported.
Integration of Biotechnology in Conventional Pea Breeding:
Transformation and regeneration protocols are now available in peas. The most common method involves Agrobacterium tumefacience mediated transformation. The major difficulty lies in the fact that this transformation is genotype specific and only a small portion of cultivars have responded to this technique.
Somaclonal variation arising from the regeneration of plants from callus, led to the use of cotyledonary meristem from freshly imbibed seed as a source of tissue for successful transformation. The use of this technology in the pea breeding is limited to proof of concept.
Partial resistance to alfalfa mosaic virus (AMV) has been reported as a consequence of transformation with chimeric virus coat protein gene, a-amylase inhibitor (α-A 1) and the promoter phytohemagglutin, both found in French-bean when transferred to pea, have shown constitutive expression and resistance to pea weevil. The expression of inhibitor (α-amylase) served to block the development of the larvae at an early stage and this resulted in less seed damage and better seed quality.
This transgenic pea product could not reach to large scale field testing due to legal issues. Transfer of herbicide resistance both as a reportable marker and a trait have also been reported, but not carried through to commercial release.
While GM crops are on increase in many parts of world with global acreage of 134 million hectares in 2009, the adverse reaction to GM crops in Europe and low rates of transfer have all contributed to the pea breeding industry not engaging in the development and release of GM peas till date.
Disease Resistance Breeding and Markers:
Pea powdery mildew, caused by Erysiphe pisi, is an air-borne disease with a worldwide distribution, being particularly important in climates with warm dry days and cool nights. Although varying levels of resistance to E. pisi have been observed in pea only three genes for resistance named er1, er2 and Er3 have been described so far. Gene er1 is widely used in pea breeding programmes and provides complete or incomplete resistance depending on the locations.
Resistance conferred by this gene has been proved to be stable and is caused by a barrier to the pathogen penetration. RFLP, RAPD/SCAR and SSR markers linked to the er1 have been identified. Gene er2 is not used commercially. The gene confers a high level of resistance in some locations, but is ineffective in others. The expression of er2 is influenced by temperature and leaf age.
Gene er2 governed resistance is based mainly on post-penetration cell death complemented by a reduction of percentage penetration success in mature leaves. AFLP, RAPD and SCAR markers linked to er2 are available. Gene Er3 was recently identified in P. fulvum and has successfully been introduced into the adapted P. sativum material by sexual crossing.
Resistance conferred by the gene Er3 is due to a high frequency of cell death that occurs both as a rapid response to attempted infection and a delayed response that follows the colony establishment. RAPD markers tightly linked to Er3 have been identified and converted into SCARs.
Pea rust has become an important pathogen of pea particularly in regions with warm, humid weather. Pea rust has been reported to be caused either by the fungus Uromyces viciac-fabae (Syn. U. fabae) or U. pisi. U. viciae-fabae is the principal causal agent of pea rust in tropical and subtropical regions such as India and China, where warm humid weather is suitable for the appearance of both the uredial and the aecidial stage.
Several sources of incomplete resistance against U. viciae-fabae have been reported. A single major gene (Ruf) has been reported as responsible for this partial resistance. Two RAPD markers have been detected flanking the gene Ruf, but both markers were not close enough to the gene to allow a dependable marker-assisted selection for rust resistance.
Only recently, pea germplasm collections have been screened to identify sources of resistance to U. pisi both under field and growth chamber conditions. No complete resistance has been identified so far. However, incomplete resistance has been observed in the collections.
All the identified accessions have displayed a compatible interaction (high infection type) both in adult plants under field conditions and in seedlings under growth chamber conditions, but with varying levels of disease reduction.
This resistance was not associated with host cell death. Preliminary results performed on F2:3 revealed two QTLs for resistance to U. pisi in the field and controlled conditions, respectively, which seems to be the reason for high percentage of the phenotypic variance.
Aschochyta blight, caused by Mycosphaerella pinodes, the teleomorph of Ascochyta pinodes (Berk & Blox) Jones, is a widespread pea disease. Ninteen QTLs associated with resistance have been reported. More recently, 6 QTLs (mp1-mp6) have been associated with resistance to M. pinodes in a cross of the cultivar Messire with P. sativum subsp. syriacum.
Resistance to fusarium wilt in peas caused by Fusarium oxysporum Schlect. f. sp. pisi race 1 (van Hall) Snyd. & Hans, is conferred by a single dominant gene Fw. The gene has been located in the pea genome by analyzing progenies from crosses involving genetic markers across all pea linkage groups.
Fw has been shown to be located on linkage group III, about 13 map units from Lap-1 and b and 14 map units from Td. The relatively large distances between these markers and Fw precludes the use of the linked markers in marker-assisted selection for wilt resistance.
DNA markers linked to recessive gene sbm-1 for resistance to pea seed-borne mosaic virus (PSbMV) pathotype P-l have been identified. Markers linked to the dominantly inherited gene En for resistance to pea enation mosaic virus (PEMV) have also been reported.
The snap pea is a type of edible-podded pea that is conspecific to field and garden peas (P. sativum L.). Edible-podded peas lack pod parchment or fibre. Most snap pea cultivars have wrinkled seeds with green cotyledons, white flowers and short internodes. Snap pea cultivars released by public and private breeders and seedsmen in 20th century in USA are as follows:
Sugar Stick, Round Podded Sugar, Sugar Snap, Sugar Bon, Sweet Snap, Early Snap, Honey Pod, String-less Sugar Snap, Sugar Daddy, Sugar Gem. Sugar Pop, Sugar Boys. Mega. Super Sugar Snap, Crystal. Sugar Lady, Sugar Star and Jessy, etc.
Among edible podded types. Oregon Sugar Podded (Mithi Phali) has been made popular at PAU, Ludhiana in 1996 through introduction. Pods are light green and devoid of parchment layer. Its average yield is about 100-110 q/ha and it is tolerant to powdery mildew under field condition.
Vegetable Pea Varieties:
In vegetable peas, early introductions from Europe and USA were found quite successful and popular in India. These included Arkel (early maturing, dwarf type, introduction from England in 1970s) and Bonneville (main season, late maturing, tall type, introduction from USA in 1970s). These introductions were obtained at IARI, New Delhi and were released for commercial cultivation after preliminary evaluation.
Arkel is still a very popular variety grown throughout the country. Arkel has 45-60 cm plant height, long well filled, sickle shape green pods with 7-9 seeds/pod. The seeds are sweet and become wrinkled at maturity. First picking is done in 60 days. It is highly susceptible to powdery mildew and rust. It has double flowers at lower nodes and single onwards. Shelling percentage is about 40%. The yield potential is 75-80 q/ha.
VL Ageti Matar (VL-7) is an early maturing variety developed at VPKAS, Almora in 1995. Plants are dwarf with dark green foliage. Pods are light green, completely filled, two pods in a bunch with 6-7 seeds/pod and 42% shelling. Its average yield is about 80-90 q/ha. Seeds are wrinkled.
Kashi Nandini (VRP-5) is an early maturing variety developed at IIVR, Varanasi in 2006 through hybridization (P-1542 x VT-2-1) followed by pedigree selection. Plants are dwarf, erect and come to flowering in 34 days after sowing. Pods are 8-9 cm long, well filled with 8-9 seeds having 48% shelling. Its average yield is 110-120 q/ha. Seeds are wrinkled.
Matar Ageta-6 is an extra early maturing variety (45-50 days) developed at PAU, Ludhiana in 1996 through hybridization (Massey Gem x Harabona) followed by pedigree selection. Plants are dwarf, erect and bear 12-15 pods with 6 seeds/pod and 45% shelling.
First picking is done in 45-50 days after sowing and about 50% of green pod yield is obtained in the very first picking. Plants are dwarf (40 cm), erect and green. Dry seeds are light green, smooth with slight dimples. It is tolerant to high temperature and its yield potential is about 60-65 q/ha. This variety is suitable for single harvest. Seeds are wrinkled.
Pant Sabji Matar 3 (Arkel x GC 141) developed at Pantnagar is similar to Arkel. however, the pods are slightly longer and attractive. Pusa Pragati developed at IARI is an early maturing cultivar with slightly straight green pods having 8-10 seeds/pod. First green pods are harvested in 60 days. It has become popular due to longer pods and higher yield potential (100 q/ha).
Kashi Udai (VRP 6) is an early maturing cultivar developed through pedigree method of breeding from the cross of Arkel x FC 1 at IIVR, Varanasi. Plant height is 58-62 cm and 50% plants bear flowers at 35-37 days after sowing. Plants have dark green foliage and short internodes with 8-10 pods/plant. Green pods are attractive, 9-10 cm long, filled with 8-9 bold seeds. Shelling percentage is 48% and green pod yield potential is 100-110 q/ha.
Among main season/late varieties requiring 100 days for first green pod harvest, the popular cultivars are Bonneville, Perfection New Line, Lincoln, Jawahar Matar-1, Jawahar Matar-4, Arka Ajeet, Azad Pea 2, Azad Pea 5, etc. These varieties are not very popular and are on decline from cultivation and the market.
Bonneville is an introduction from USA and made popular by IARI. Plants are medium tall (60-70 cm) come to flowering in about 60 days having two pods per peduncle. Pods are light green, straight having 6-7 seeds/ pod with 45% shelling and seeds are green, bold and wrinkled. Its average yield is 100 q/ha and it is susceptible to powdery mildew. Green pods are harvested in 100 days.
Arka Ajit (FC-I) is a variety of medium maturity group developed at IIHR, Bangalore in 2006 through multiple cross involving Bonneville, IIHR 209 and Freezer 656. Pods are 8-9 cm long with green bold seeds having 55%, shelling. It takes 90 days from sowing to first picking. It has resistance to powdery mildew and rust. Its average yield is about 95-100 q/ha.
Azad P-5 (KS-225) is late maturing variety developed at CSAUAT, Kanpur in 2006. Plant growth is medium with straight pods full of grains and bearing may be extended up to March. Its average yield potential is 95-105 q/ha and has resistance to powdery mildew. Pant Sabji Matar-4 (Arkel x HFP 4) developed at Pantnagar is late maturing and is classified as leafless type as leaflets are converted into tendrils.
Field Pea Cultivars:
In India, in initial stages, local cultivars were subjected to mass/pure-line selection and released. A very popular high yielding bold seeded cultivar T 163 was made popular in UP after purification of a local material from Buland Shahr through the efforts of Economic Botanist (Pulses) of the then Govt. College, Kanpur and now CSAUAT, Kanpur.
The area under these varieties is on decline due to stiff competition from wheat and consumers resistance to adopt these in their daily diet.
However, some popular field pea cultivars are listed as follows:
UP : Type 163, Rachna, DMR 11, B 22, Pant P 5, HUP 2
Bihar : BR 2, B 12 Swam Rekha, Rachna, DMR 11, T 163, Hans, HUP 2
West Bengal : B 22, B 12, Rachna, DMR 11, KUP 2
Delhi : Hans (L 116), Harbhajan (EC 33866), Rachna, DMR 11, Pant P 5
Maharashtra : Khoperkheda, Rachna, DMR 11, JP 885, Pant P 5
Himachal Pradesh : Kinnauri, Rachna, Hans, HPP 1
Punjab : PG 3, Rachna, Hans, Pant P 5
Haryana : Rachna, DMR 11, PG 3, Pant P 5
Rajsthan : Rachna, DMR 11, RP 3, T 163, Pant P 5
MP : Rachna, DMR 11, T 163, Hans, Pant P 5, JP 885
Rachna (T 163 x T 10) developed at CSAUAT, Kanpur was released in 1980 by UP State Variety Release Committee to replace T 163 as Rachna was claimed to be resistant to powdery mildew.
HPP 4 (Aparna) developed at CCS HAU, Hisar from a cross of T 163 x EC 109196 released in 1988 is classified as leafless type. It takes 145 days to mature and the grain yield potential is 25 q/ha. It is reported to be resistant to powdery mildew. A general survey of pedigree of early maturing vegetable peas and the field peas shows that Arkel is frequently used as one of the parents in case of vegetable type cultivars and T 163 in case of field pea cultivars.
Future Prospects of Pea:
The area under field peas in India is likely to stagnate or shrink in future due to competition from irrigated wheat, and more remunerative pulses with wider consumers’ preference. This is evidenced by the fact that breeding and release of powdery mildew resistant field pea cultivars viz. Rachna, DMR 11, HFP 4, Pant P 5, and JP 885 has failed to boost the production and productivity.
Under these circumstances, field pea breeding programme are likely to be operated on a lower scale. However, vegetable peas are becoming increasingly attractive despite the fact that majority of the commercially acceptable cultivars are susceptible to powdery mildew and rust. Therefore, breeding for resistance to these two diseases combined with emphasis on freezing and canning attributes should be encouraged.
Development of such cultivars in the background of vegetable pea varieties, Arkel and Bonneville must get priority on the part of vegetable breeders as a challenge to them. Marker assisted selection is likely to be used in applied breeding programmes. Commercialization of transgenic pea seems to be feasible in near future.