By Bhavyasree RK

PhD Genetics and Plant Breeding

Crop wild relatives (CWR) are wild plantspecies closely related to crops, includingwild ancestors

They have an indirect use as gene donors forcrop improvement due to their relatively closegenetic relationship to crops

They are an important socio‐economicresource

that offer novel genetic diversity required to

maintain future food security.

Two cultivated (2 n = 24, AA) ◦ Oryza sativa

◦ O. glaberrima

22 wild species (2 n = 24, 48) - AA, BB, CC,

BBCC, CCDD, EE, FF, GG, KKLL, and HHJJ

genome types

Sanchez et al, 2013

African gallmidge,

nematodes,

nematodes

Stemborer

Oryza minutaBPH, GLH

Resistance to striped stemborer

Oryza brachyanthayellow stemborer, leaf folder,

whorl maggot

Oryzaofficinalis

Thrips,BPH,GLH,WBPH

Oryza ridleyi

BPH,BB,zigzag leafhopper

stem borer,whorl maggot

Wheat

Cultivated species

Common wheat (Triticum aestivum)

2n=6x=42

Durum wheat (T. turgidum)

2n=4x=28

Wild species

Six diploids

2n=14

Seven tetraploids

2n=4x=28

Three hexaploids

2n=6x=42

F1 sterileChromosomal doubling

F1 sterileChromosomal doubling

Evolution of hexaploid wheat

Ploidy Species Common name Genome

DIPLOID(2n=14)

Triticum boeticum(T. aegilopoides)

Wild einkorn AA

T. monococcum einkorn AA

TETRAPLOID(2n=28)

T. dococcoides Wild emmer AABB

T. dicoccum emmer AABB

T. durum Macaroni wheat AABB

T. persicum Persian wheat AABB

T. turgidum River wheat AABB

T.polonicum Polish wheat AABB

T.timopheevi - AABB

HEXAPLOID2n=42

T.aestivum Common/breadwheat

AABBDD

T.compactum Club wheat AABBDD

T.sphaerococcum Dwarf wheat AABBDD

T.spelta Spelta wheat AABBDD

T. macha Macha wheat AABBDD

TRAIT LOCUS SOURCE

Hessasin fly H21 S. cereale

H23,H24 T. tauschii

H27 Ag. ventricosa

Cereal cyst nematode

Cre3 T. tauschii

S. nitidum - Found in kodai hills. Processes for shoot fly resistance and dormancy.

Heterosorghum, Parasorghum and Stiposorghum showed high levels of resistance to the spotted stem borer.

Wild species S.spontaneum

S.robustum

S.spontaneum, 2n=40-128

Wild species, found in Indonesia and New Guinea.

Imparted tolerance to stress, diseases and pest, hardiness and ratooning ability to present day cultivars.

G.thurberi G.anomalum G.raimondii G.tomentosum