Laila Ikase

• Disease-resistant apple cultivar breeding
• Apple genetic resource research
• Apple cultivar testing
   

Disease-resistant apple cultivar breeding

The objective of the apple breeding programme is to obtain and select apple cultivars that are adapted to the climatic conditions of Latvia and the Baltic region:

• that have high quality fruits (incl. market quality, flavour, biochemical composition and storage),
• that are winter-hardy, productive, produce regularly, and are easy to cultivate (compact tree, minimum formation, minimum necessity for fruit thinning, holds the fruits well on tree),
• that have complex resistance to the major apple tree diseases common in Latvia (scab, canker, fruit rots, mildew), with various periods of consumption.

The work in apple breeding was carried out in several stages:

1. Testing the hybrid pool that was acquired by Pēteris Upītis, selecting candidate cultivars (1995-1999).
2. Taking over and testing the breeding material that was obtained by R. Dumbravs at "Iedzēni", incl. hybrid combinations with scab immunity genes Vf (Rvi6) and Vm (Rvi5) (1993-2016).
3. LatHort apple breeding programme (1994-current). The programme uses the research results on genetic resource collection and the analysis results on gene markers, special attention is paid to fruit quality indices.

The programme includes scab resistance, columnar habit (Co) and anthocyanin colour donors.
Cultivars created during the breeding process have been tested also in other countriesof the Baltic region. Several of these cultivars have been approved as perspective in Estonia, Finland, Sweden; two cultivars have been registered in Belgium for cultivation in Ardennes mountain region. The cultivar 'Dace' deserves a special mention since it has been recommended for commercial cultivation in Latvia and is approved as perspective in Estonia.
 
Apple genetic resource research

The genetic resource study, description and descriptor adaptation to regional climate conditions was started in Sweden as a joint project (1995, 1998-2000). The methods developed during this project have been applied to research in Latvia.

The genetic resource study and utilisation is significant for expanding the genetic base of apple breeding.

The genetic resource collection in Latvia maintains over 100 apple cultivars of local origin, which are well-suited to the regional climate conditions and possess other valuable properties. Their successful use in breeding has been prevented by insufficient data availability. It is especially important to identify disease-resistance genes in local cultivars and to find potentially new sources of resistance. Within the scab research project, in collaboration with the Institute's Unit of Plant Pathology, several genotypes have been selected, and the research continues.

Another relevant issue is the rapid erosion of genetic material due to the current changes in local orchards and farms . That is why expeditions for collecting genetic resources were organised in the early 20th century. Approximately 200 apple tree samples were collected and tested in the collection trial garden. Several selected genotypes have been included in the genetic resource base collection. Collection, evaluation and description of genetic resources continue. 

Apple cultivar testing

Although the assortment of the commercially cultivated cultivars in Latvia has relatively stabilised, horticulturists have expressed the necessity for new, better cultivars. Apple trees are one of the species to which, when introducing a cultivar, compatibility with local cultivation and market conditions is crucial. The greatest difficulty is to combine the cultivar winter-hardiness with good quality fruits and storage in the Latvian climate conditions.

The initial cultivar testing included apple cultivars from many countries, mainly from Latvia, Estonia, Sweden, Russia and Belarus. Research on the biological properties, fruitfulness and fruit quality is on-going. During exhibitions and Field Days, consumer and plant grower surveys are carried out.

Over the recent years, special attention has been dedicated to research on fruit quality and storage, which is influenced by the  growing technologies, cultivar, fruit thinning intensity, harvest period, storage conditions. Within the framework of VPP-5 (2010-2014) project, guidelines on fruitlet thinning for the tested cultivars have been developed. Research on factors that influence fruit storage continues (SRP AgroBioRes project No. 2 (FRUIT) (2014-2020).

In recent years, Latvian producers have increased interest in apples suitable for cider production. This interest has created a need to find cultivars that are suitable for this purpose and are compatible with Latvian climate conditions. Research has been conducted on cultivars and hybrids that are potentially suitable for making cider, on the biochemical composition and suitability for production.

Different clones of many older varieties still exist. It is necessary to select the clones that are recommended for cultivation. During the testing of 9 'Baltais Dzidrais' (‘White Transparent’) clones, 5 different genotypes were identified using gene markers.  A field trial of their productivity and fruit quality continues.
Rootstocks are an important factor that has a direct impact on cultivar growth, productivity, fruit quality. Currently, three winter-hardy rootstocks of Finnish origin are being tested with two cultivars. A perspective rootstock MTT 4 has been selected.

Based on the research results,several new apple cultivars have been selected and recommended for further testing in commercial and organic orchards. These cultivars have been promoted in lectures and publications.

Major accomplishments:

REGISTERED CULTIVARS: 

• Cultivars registered in Latvia -  15 (co-author or author):

  •  ‘Ausma’ (1999-2015), ‘Magone’ (2002-2015), ‘Ella‘, ‘Agra’ (2002), ‘Baiba’  (2008), ‘Dace’, ‘Gita’, ‘Edite’, ‘Ligita’, ‘Roberts’ (2008), ‘Uldis’, ‘Zane’ (2011), ‘Felicita’, ‘Inta’ (2023), ornametal apple  ‘Karlens’ (2021)

• Applications for cultivar registration  - 13 

  •  ‘Monta’ (2012),  ‘Lora’, ‘Auce’ (2020).  Asnate’, ‘Dinija’ (2022), ‘Juris’, ‘Valentino’ (2023), ‘Inara’, ‘Katrīnīte’, ‘Raivo’, ‘Sarmīte’, ornametal apples  ‘Antonija’, ‘Dūdars’ (2024)

• Cultivars without co-author rights protection: 

  • ‘Lienīte’, ‘Paulis’, ‘Saulesmeita’, ‘Čakstes Auči’ 

• Registered in EU (Belgium)  – 

  • ‘Edite’ (COV Nº1804, Bruxelles 21/02/2011), LVAI (LSIFG), 

  •  ‘Ligita’ (COV Nº1803, Bruxelles 21/02/2011), LVAI (LSIFG), representative breeder Jacques Paquot

AWARDS:

Pauls Lejiņš Award for achievements in apple breeding (2023)

NEWEST PUBLICATIONS (2020-2025):

1. Ikase L., G. Lācis. History and breeding of apples in Latvia: crossroads of geography and challenges of climate.  8 p. (akceptēts: Acta Horticulturae)
2. Ikase L. 2024. Columnar and crab apple breeding in Latvia. Acta Hortic. 1412, 217-222. https://doi.org/10.17660/ActaHortic.2024.1412.33

3. G. Lācis, K. Kārkliņa, L. Ikase. 2024. Marker-based identification of potential scab resistance donors in Latvia apple collection. Acta Hortic. 1412. ISHS 2024. DOI 10.17660/ActaHortic. 2024.1412.6 

4. P.Gornas, I.Mišina and L.Ikase. 2022. Crab Apple (Malus spp.) Seed Tocopherol Profile: Impact of Genotype, Species, Purpose and Rootstock. Agronomy 2022, 12(11), 2736; https://doi.org/10.3390/agronomy12112736

5. Zelmene, K., Kārkliņa, K., Ikase, L., Lācis, G. 2022. Inheritance of apple (Malus × domestica (L.) Borkh) resistance against apple scab (Venturia inaequalis (Cooke) Wint.) in hybrid breeding material obtained by gene pyramiding. Horticulturae, 8, 772. https://doi.org/10.3390/horticulturae8090772

6. Ikase L., I.Drudze, G.Lācis. 2022. Current achievements of the Latvian apple breeding program. Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences., vol.76, no.4, 2022, pp.424-431. https://doi.org/10.2478/prolas-2022-0066
7. Ikase L., Rubauskis E. 2021. Evaluation of Romanian apple cultivars in Latvia. Fruit Growing Research, Vol. XXXVII, 2021, pp.27-32; DOI 10.33045/fgr.v37.2021.04 https://publications.icdp.ro/publicatii/lucrari%202021/04.%20Ikase%20Laila.pdf
8. Univer, T. and Ikase, L., 2021. Breeding apple scab resistant cultivars in Estonia. Acta Horticulturae 1307, 7-12. https://doi.org/10.17660/ActaHortic.2021.1307.2
9. Grāvīte, I., Dēķena, D., Kaufmane, E. and Ikase, L. (2021). Intensive type plum plantations in Latvia. Acta Hortic. 1322, 221-22 DOI: 10.17660/ActaHortic.2021.1322.32 https://doi.org/10.17660/ActaHortic.2021.1322.32
10. Krasova N., L.Ikase, Dz.Dekena, and A.Galasheva, 2021. Use of apple tree gene pool to create adaptive cultivars with high quality fruits. E3S Web of Conferences 254, 01033 (2021) FARBA 2021, 12 p. https://doi.org/10.1051/e3sconf/202125401033
11. Ikase L., E.Rubauskis. Evaluation of Estonian apple cultivars and hybrids in Latvia.  Agronomy Research, 18(S4), 2701–2714, 2020. https://doi.org/10.15159/AR.20.221
12. Krasova N., L.Ikase, Dz.Dēķena, 2020. Evaluation of the main biological and production traits of Latvian apple cultivars in the conditions of Central Russia. Agronomy Research,18(S4), 2727–2742, 2020. https://doi.org/10.15159/AR.20.222
13. K. Juhnevica-Radenkova, D. A.Moreno, L.Ikase, I.Drudze, V.Radenkovs. 2020. Naturally occurring melatonin: Sources and possible ways of its biosynthesis. Comprehensive Reviews of Food Science and Food Safety. Vol . 19, issue 6, November 2020, p.4008-4030. https://doi.org/10.1111/1541-4337.12639

5 most important popular science publications:

• Skrīvele M., Ikase L. 2013. Latvijas ābeles [Latvian apples]. R., „Jumava”, 136 lpp. (book, in Latvian)
• Kask K., L.Ikase. 2008. Lätis on palju uusi puuviljasorte [New Latvian fruit crop cultivars] // Maakodu, Nr. 12, 66.-68. (in Estonian)
• Skrīvele M., Ikase L., Kaufmane E., Blukmanis M., Strautiņa S., Ruisa S. u.c. 1999. Ilustrēts augļu koku un ogulāju šķirņu katalogs [Illustrated fruit and berry variety catalog]. Valsts Dobeles DSIS, Dobele, 323 lpp. (book, in Latvian)
• Ikase L., 1999. Ābolu avīze [Apple newspaper]. SIA Lauku Avīze, 64 lpp. (in Latvian)
• Ikase L., 1997. Iestādi savu plūmi [Plant your plum]. Izd. Dārzs un Drava, Rīga. 56 lpp. (book, in Latvian)